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егэ
егэ 2021
математика
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подготовка к егэ по математике
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решу егэ
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ященко
ященко 2020
задание 18 егэ математика профиль
егэ профильная математика 2021
ященко егэ 2021 профильный уровень
параметры
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уравнение с параметром
задание 18
найти все а
что такое параметр
14
теорияшколапифагора
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  • ruRussian
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00:00:03
the more likes we get, the more
00:00:06
people will see this video parameters that is
00:00:08
18 problem is solved by only a few
00:00:10
percent of people and the more difficult the parameter
00:00:14
than for example problem 13
00:00:15
why 13 will solve everything and the parameter
00:00:18
units why I think because 13
00:00:22
the task is quite typical
00:00:27
there is an algorithm that can be solved
00:00:29
most likely this is an electrical equation
00:00:31
you decide there, well there are only a few
00:00:33
types of these elementary equations in this
00:00:36
solve plus or minus in similar ways
00:00:38
always use limited
00:00:40
there are several formulas there
00:00:43
all the time in function b you can select by
00:00:45
circles for example or double
00:00:46
inequality as you are used to, that is
00:00:48
is there a clear solution method yes you have
00:00:51
a clear solution plan on the thirteenth
00:00:53
template, roughly speaking, you decide which one
00:00:55
you have it in your head that if I tell you
00:00:58
I will say that I found a template solution
00:01:02
18 tasks, well, not all 18 tasks yet, but
00:01:07
huge type of tasks
00:01:09
a huge popular type of problem where
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we need to find for what a the equations has
00:01:14
exactly one root on the segment if y
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you have a big equation that has
00:01:19
there are a lot of roots, maybe 23 roots
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so you need to find and at which
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out of these two, three will remain to feed
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only one if the condition is when
00:01:29
equation with some muda
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has exactly one root on the segment because
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again the equation has the only one
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the root of the interval is
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the only root on the segment
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has exactly 1 course if the condition
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such problems are solved by
00:01:40
a certain pattern and today I
00:01:44
I’ll tell you about the template and we’ll sort it all out
00:01:46
these tasks, that is, today you can
00:01:48
solve all these problems and if you are at the game
00:01:50
there will be a task with similar conditions and this
00:01:52
super popular type of task then you are more likely to
00:01:55
in total you will score 4 4 ​​primary points
00:01:57
that is, this task is the most significant in the game
00:01:59
and you will score maximum points
00:02:02
I'm recording a video course right now
00:02:05
according to the parameters which will be released on March 31 and
00:02:08
before recording the video solutions I made
00:02:10
list of all tasks
00:02:12
I'm writing it down and suddenly I realize that
00:02:14
that's when I write down task number 20 of
00:02:17
list I have already decided this many times
00:02:21
in the same way as the twentieth is solved
00:02:23
task and look and understand what
00:02:26
the previous 20 tasks using this method you can
00:02:29
I had to solve 8 problems 820 and I understand that
00:02:32
this is a super popular type of parameters and
00:02:36
everything is solved one way
00:02:38
I need to record a video that's why I
00:02:40
Now this is a video and I’m recording what it’s all about
00:02:43
method means using a specific example here
00:02:47
you have a court equation and you need
00:02:48
find for which a there will be exactly one
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root on segment where to start right
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throw part to the left, well, great
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obviously started to bring out the general
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right side time to take out the general
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the product is equal to zero when at least
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one of the factors is zero + 1 for
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hang it and plus x should be in
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segment from zero to one all in one
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the system can be pushed in, so you solve these
00:03:10
elementary equations you have x 1 x
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toroid
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question at what a x 1 is a root
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equations on the segment, that is, x 1 should
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satisfy now and
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lie on the segment from 0 to 1 by 1 2 and so on
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lies on the segment for this reason I
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I'm not including this here, I'm just being rude
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speaking of yes for for ics for x 1 I find not
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I understand that with these a x 1 is
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root of the equation on the interval a x 2 at
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what kind of
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is a root on the segment x 2 must
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lie on the segment and remove stabbed even
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I find for what a x 2 is a root
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on the segment then taking into account that in and to
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sides are a x 1 of can coincide with
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old at some point and I find at
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which a x 1 coincides with k old then
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there is when we have, like, two roots, but they
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they coincide they are the same here and then in
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at the end I make a number line and where
00:04:03
I show at what and how many roots here
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with such and there are no roots for such there are no roots for
00:04:08
there is only one root
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with such a there are two different roots here
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there are two different roots, but not
00:04:13
coincide, you know there is one root
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and I write down at what time and it turned out only
00:04:18
I circle them with one root and write them in
00:04:20
answer end here is the solution algorithm
00:04:24
it’s clear there the equation can be a little
00:04:26
be different today I picked up 14
00:04:30
tasks we will analyze 14 tasks video
00:04:33
very long but super useful because
00:04:35
if you get a task in the game where
00:04:37
there will be an equation with a j and we need to find
00:04:39
one root on the segment most likely she
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solved this way and you can dial 4 4
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primary points even if you are earlier
00:04:47
parameters of communication were decided by I think you
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you can understand this video and
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We’re not interested at all, so it turned out
00:04:53
can you figure it out?
00:04:54
then write in the comments you are with this
00:04:57
as easily as I do now you decide
00:04:59
such tasks or something didn’t work out
00:05:01
write in the comments if possible
00:05:04
someone managed to solve it for the first time
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parameter then write about it too
00:05:07
interesting, did you like this?
00:05:09
did you understand the explanation, the solution algorithm
00:05:12
or not, find all the values ​​for each
00:05:16
of which the equation has exactly one
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root on the interval from 0 to 1
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the obvious start is the right side to the left
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reroll remove general so root from
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2 x minus 1 times ln 4x minus a
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minus
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rewrite
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equals zero, then take the root beyond
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buying up
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brackets remains the difference of logarithms
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when the product is zero when although
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if one of the factors is equal to 0 2
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each of the factors exists in general
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equate to zero plus add water
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for plus we say that x is from zero to one
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that is, 2x + 1 can be taken as the root equal to
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zero
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I will write in detail although it was already possible
00:06:14
Of course some transformations need to be done
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well, you still need a few parameters
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more details equal to zero
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set + a to z we have what 2x
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minus 1 must be greater than or equal to 0 4
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x minus a must be large or
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islands 5x plus a must be greater than 0
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strict and x must be between 0
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to one
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such a system we get the root
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is equal to zero when when the radical is equal to
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zero, that is, x is equal to 1 2 there and here
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it is also easy to solve the equation l n right
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throw Elena, remove sex
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leipzig with the right subject is shorter
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it turns out for us
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system can well the first equation is the root
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remove the root 2 x minus 1 equals zero 2x
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is equal to 1 x is equal to 1 2 is x 1 x 1 is 1 2
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x 2 what is equal to l n to the right we remove Elena
00:07:24
4x minus a equals 5x plus a
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and jambs to the left errors to the right x equals
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minus 2 and we are these x 2 this is -2 and so 2 x
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minus 1 large equals 0 x greater or
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equals than 1 to the right and divide by 2 1 2 well
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let's rewrite this 4x minus a should be
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greater than 0 5 x plus a must be greater than 0
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x must be between zero and one
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so we have two roots, well, more and
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equals 1 2 and from zero to one find
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let's find the suppression now, that is
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it turns out we already have five lines
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busy
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x 1 equals 1 2 x 2
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is minus 2 x must be greater or
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is equal to 1 2 and lies in the segment
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from zero to one if we find
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intersection then it turns out that x should
00:08:27
be from 1 2 to one so well, plus y
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yes for 4 minus more than 0 and 5 x plus a
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greater than 0 so now let's find out when
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what a x 1 is the root of the equation x
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1
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it is equal to one-half is the root
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equations for a satisfying what
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requirements first x 1 1 2 he must
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lie in the segment from 1 2 to one he and
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it lies like that plus it should even satisfy
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with passion he must satisfy two
00:09:04
inequalities 4x minus a greater than 0 and 5 x
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plus a is greater than 0
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we substitute the second one under x1 and it turns out 4
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multiply by one half
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minus a more than 0 5 by one second plus a
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more than 0 is obtained and less than 2 and
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more than -2 and a half conclusion, well
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less than two more than minus 2 and a half
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this means that a belongs to minus
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two and a half to two so here's the output in
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than with
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and with proper Andrey from minus two with
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half to 2 x 1 equals 1 2 is
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root of the equation on a given interval
00:10:00
is the root of the equation and for what
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aek 2 is the root of the equation a and ko
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the second one which is equal to minus 2 a
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is the root of the equation for a
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satisfying the following requirements
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must lie on the segment from 1 2 to
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units
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it’s no longer obvious that he’s lying there
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so we must say a stroke for must
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lie
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for some from 1 2 to unity and he
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must satisfy o dose 4x minus a
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more than 0 and 5 x plus and more than 0 some
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it seems that it was possible not to write from them or
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baba because this root came from
00:10:44
equations where these logarithms were or not
00:10:48
Still, it’s better to check in short
00:10:50
don't even think about it and just system
00:10:52
write down to be on the safe side let's say
00:10:55
this means we have such a system
00:10:57
instead of exe we substitute -2 and here is 1 2 to
00:11:04
units instead of exe to -2 and instead of exe to
00:11:14
minus 2 a
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it turns out so let's go to minus 1 2
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multiply it turns out a minus 1 4 minus
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a half
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the icons unfold because
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negatively multiplied further
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minus 8x minus and this is minus 9 and greater than 0
00:11:45
minus 10 plus
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and this is minus 9 and yes it’s not automatic
00:11:52
holds o even a both restrictions in
00:11:55
they turn into the same thing, that is
00:11:57
it turns out it was, so let's write it down
00:12:00
double inequality more common in
00:12:02
in the usual form, that is, a should be from
00:12:04
minus 1 2 inclusive up to minus 1 4 and
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there closely minus 1 multiply it turns out a
00:12:10
must be less than less than zero not by
00:12:14
multiply minus 1 and divide by -9 and
00:12:18
it turns out a is less than zero a is less than zero
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in this case from minus 1 2 to admins 1 2 to
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minus 1 4 so well, the segment from minus 1 2 to
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minus there by 4 it is already less than zero then
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there is this segment left at baptism
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conclusion for a for a proper segment from
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minus 2 to minus 1 4 x second which
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was equal to -2 and is the root
00:12:54
equations on a given interval
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root of the equation so let's now
00:13:05
find out at what point they coincide 1 2 and
00:13:08
minus 2 x 1
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matches the old iq if anything
00:13:18
occurs if x 1 which is equal to 1 2
00:13:25
equal to and which, that is, equal to minus 2 a
00:13:28
but we find that we need to divide one half
00:13:33
at -2 it turns out minus 1 4 output at a
00:13:39
equal to minus 1 4 x 1 becomes equal
00:13:46
and to the old one now let's apply a
00:13:49
which influence whether x 1 or 2 are
00:13:53
whether the equations are roots or not, that is, we
00:13:55
put on the number line and all the important ones
00:14:00
and the number line and we plot it like this x 1
00:14:05
is the root of a of minus two c
00:14:07
half to 2 x 2 from minus 0 5 to minus
00:14:13
0 25 and minus 0 25 must be turned on again
00:14:17
and so two to the right of all here is chapane minus 2
00:14:22
with half to the left of all there is still minus 0
00:14:28
5 and minus zero 25
00:14:36
we are interested in
00:14:37
a less than minus 2 and a half a
00:14:41
exactly, exactly minus 2 and a half a from
00:14:45
minus two and a half to minus 0 5 a
00:14:49
exactly -05 and from minus 0 5 to minus zero
00:14:56
25
00:14:57
a exactly minus zero 25 a from minus 0 25 to
00:15:04
2 a is equal to 2 and a is greater than 2 so let's
00:15:09
let's make small sticks
00:15:26
and less than minus twenty so let's
00:15:29
of x 1 is the root of minus two s
00:15:32
half to two not inclusive then
00:15:35
there is x 1 is the root here and it
00:15:38
equals something I forgot 1 2 x 1 equals 1
00:15:43
2 here x 1 equals 1 2 here x 1 equals 1 2
00:15:48
here without 1 is equal to 1 2 here x 1 is equal to 1 2
00:15:54
here everything from minus two and a half to
00:15:57
two where inclusive so and x 2 is
00:16:01
root from -1 2 to minus 1 4 inclusive
00:16:04
that is, x 2 is a root and equals
00:16:07
minus 2 and here x 2 is the root hey
00:16:10
rhine -2 here x 2 is the root equal
00:16:13
minus 2 here if a is equal to minus 0 5 then x
00:16:18
1 Ryan turns out to be one so here he is
00:16:21
different all the time but here
00:16:23
if a is equal to minus 0 25 then x 1 is equal to 1 2
00:16:26
and we have two
00:16:29
matching roots, that is, only one
00:16:31
root understand 2 matching that is
00:16:34
just one root
00:16:37
except if a is less than minus 2 s
00:16:40
half of you don't see here at all
00:16:41
it turns out there are no roots here
00:16:43
if a is equal to minus 2 and a half also not
00:16:46
turned out to be roots if
00:16:50
and here it is from minus 2 and a half to
00:16:52
minus 0 5 st we have one root if a
00:16:55
-05 two different roots if from minus 0 5
00:16:57
to minus 22 different roots if minus 0
00:17:00
25 then 2 matching roots that is one
00:17:02
root from -25 to 2 1 root
00:17:05
if a is equal to 2t there are no roots if a is greater
00:17:11
there are no two roots
00:17:14
the question at which a will be only one
00:17:18
root at what and we will have only one
00:17:20
root on the segment so it suits us a
00:17:23
these ones will only have x 1 as a root
00:17:25
and equals minus 0 5 does not fit
00:17:28
this is not suitable this is suitable for him
00:17:30
there will be two matching ones, that is, one
00:17:32
the root is also suitable, we write everything
00:17:35
answer
00:17:39
there will be one root
00:17:41
from minus 2 and a half not inclusive
00:17:44
up to -0.5 not inclusive and from minus 0.25
00:17:55
inclusive up to because a equals minus
00:18:00
0 25 gives two identical roots to two
00:18:05
not inclusive, also with no two
00:18:07
roots
00:18:08
everything will come x will be exactly the same
00:18:10
solution since we solved with the equation and
00:18:13
the right part was transferred to the left, taken out
00:18:15
common beyond parenthesis root root is zero
00:18:18
or the difference of logarithms is 0 plus 1
00:18:21
plus x from zero to one
00:18:23
solved these elementary equations
00:18:25
got x 1 x 2 + z + x from zero to
00:18:28
units Well, we transformed the ladies a little and now x
00:18:32
1 is the root when when it
00:18:34
satisfies all the limitations of the muse and
00:18:36
is in the interval from 1 2 to units well
00:18:38
well so in 1 5 2 to album units
00:18:41
that's why they only demanded the image
00:18:42
for him to do, here he does
00:18:45
Odessa satisfies the drive of such a
00:18:47
good x 2 satisfies there for the drive
00:18:50
so cool now they match
00:18:53
if a is equal to minus 1 4 understandable but
00:18:56
number line shown
00:18:57
important and showed at what and how much
00:19:01
roots and circled tea at which only
00:19:03
one root turned out to be such a task
00:19:07
find all values ​​for which
00:19:09
equation has a single root at
00:19:11
segment from 0 to 1
00:19:12
how to start a square is equal to a square
00:19:16
how to start, well, it’s elementary
00:19:19
right side to the left with minus the difference
00:19:21
squares we paint to accept very
00:19:26
easy to start obvious sometimes unclear
00:19:30
where to start and here in my opinion it’s more obvious
00:19:32
nowhere like ln x plus 2 a
00:19:39
minus so ln x plus 2 squared
00:19:50
difference of squares is equal to zero difference
00:19:52
we write squares according to the formula
00:19:54
draw a square just in case I
00:19:56
I'll show you because there are people in whom
00:20:01
for some reason he refuses
00:20:04
brain work with simple formulas in
00:20:08
more complex applications here
00:20:11
ordinary difference of squares that is a
00:20:12
square minus b square we see and can
00:20:14
replace with the product of two brackets
00:20:16
and minus b by plus would, that is, it turns out
00:20:18
2 x plus
00:20:21
ln x plus 2 minus this expression is
00:20:27
there is minus 2x minus date bracket
00:20:30
now the signs
00:20:31
I reveal it turns out plus ln x + 2
00:20:35
multiply by the product a multiply by
00:20:41
the sum of two terms, that is, 2 x plus
00:20:44
ln x 2 + 2x minus
00:20:51
ln x plus 2 so when we are the difference
00:20:57
squares have been painted, still need to be hung dz
00:21:01
yes it equals zero let's simplify 2 x
00:21:07
minus 2 x destroyed it turns out l n plus 1 is 2
00:21:10
identical allene 2 ln x plus 2
00:21:16
you need to multiply by here Elena mutually
00:21:19
destroyed remains 4 x equals zero
00:21:25
This is the equation we got from
00:21:28
initially you got this
00:21:29
equation plus must be required so that
00:21:31
od for fulfilled that is necessary
00:21:34
demand that we also have x plus 2 a
00:21:37
should have been greater was greater than 0 and
00:21:42
it is necessary that x lies in the interval from zero to
00:21:45
units, I’ll also push this straight into the system
00:21:47
there was no need to write it down
00:21:50
so on next when the work
00:21:53
equals zero when at least one factor
00:21:55
equals 0 authors exists, that is, we have
00:22:00
or l.n.
00:22:02
well two is not equal to zero 4 is not equal to zero
00:22:04
that is, either x is equal to zero or ln is equal
00:22:07
understand zero or ln x plus 2 and is equal to
00:22:11
zero
00:22:12
or x is equal to zero x plus 2 must be
00:22:19
more than 0
00:22:20
x must be from 0 to one so ln
00:22:26
equal to zero when when well ln means in
00:22:30
the base of the little box and we build it into the first
00:22:33
to the zero power and it turns out 1, that is
00:22:35
pornographic one elementary
00:22:38
everyone understands the logarithmic equation
00:22:39
which one to decide of course yes that is x plus 2
00:22:43
and it is equal to one x is equal to zero x plus 2
00:22:51
and should be greater than 0, by the way, please note
00:22:54
express 2 is equal to one, that is, oh yes for
00:22:56
is executed at one of the roots well
00:22:58
no matter, can we go there again, well, in general
00:23:05
solve it will not be superfluous to express x in short
00:23:12
that is, let me start with a zero x
00:23:15
Let 1 be equal to zero and x 2 be equal to 2
00:23:19
we'll throw 1 -2 to the right, but we have two
00:23:23
root
00:23:25
dc and x must have a zero to
00:23:30
units is good if each of the roots
00:23:36
satisfies hell for
00:23:37
and is from zero to one then we have
00:23:39
there will be two roots and we need it to be
00:23:43
the only root for the crack from zero to
00:23:45
units means the first root must be
00:23:47
suitable but the second one is not or vice versa 1
00:23:50
inappropriate and the second one is suitable or
00:23:52
they must match, let's find out when
00:23:55
which ones x 1 are suitable
00:23:58
x 1 it is equal to zero for what a for a
00:24:05
satisfying worst for and if x is from zero
00:24:10
to one but x is equal to zero it is from zero to
00:24:12
units include on the segment yes that is
00:24:14
with a satisfying y it is even possible
00:24:16
say when satisfying
00:24:18
inequality x plus 2 greater than 0 x equals
00:24:23
substitute zero for zero
00:24:26
it turns out that two a is greater than 0, that is, a
00:24:31
more than 0 output
00:24:33
the conclusion is that when a is greater than 0x 1
00:24:39
equal to zero will be the root
00:24:41
equations for other a x 1 will be
00:24:44
violate decrees
00:24:45
so that means at and more that is not
00:24:47
will be curation aprio more
00:24:49
0x 1 will be the root of the equation
00:25:02
ikos 2 which is equal to 1 minus 2 and he
00:25:11
is the root of the equation for what a
00:25:13
with a satisfying means dc well
00:25:23
although we have recently found out what ode
00:25:26
forgets to do it, no problem
00:25:28
let's figure it out again and he should be in
00:25:31
segment from zero to one even if with
00:25:33
zero it’s clear that he’s a unit in the squads
00:25:35
already 0 then with the expression containing and not
00:25:39
it’s clear we need to understand at what conditions it will be
00:25:41
from zero to one so from this
00:25:48
must be fulfilled therefore often we
00:25:50
we substitute yes under x 1 -2 it turns out
00:25:53
one minus 2 plus 2 a greater than zero to at
00:25:57
anyway, that’s how we understood it and 1 -2 should
00:26:00
be from zero to one first
00:26:03
inequality gives us the answer and any in
00:26:06
any
00:26:07
one is more than Olya, and in double
00:26:11
inequality how to solve we subtract
00:26:12
one from all sides, that is, minus 1
00:26:15
minus 2 and zero and multiply by -1 second
00:26:21
that is, it will be a 1 2
00:26:25
zero when on a negative number
00:26:28
multiply the icons unfold that is
00:26:31
output at a
00:26:37
with proper from 0 inclusive to 1 2
00:26:47
x 2 will be the root of the equation and 2
00:26:51
equal to 1 minus 2 will be the root
00:26:54
equations
00:27:01
root of the equation
00:27:12
yes even
00:27:15
roots can coincide zero and 1 -2 can
00:27:19
coincide
00:27:21
let's find out at which ones and they coincide
00:27:24
x 1
00:27:26
coincides, that is, there will be two roots but
00:27:29
identical
00:27:30
coincides with and to the old ones if anything
00:27:33
happens if x 1 is equal to zero
00:27:38
coincides means equal to the old 1 -2
00:27:41
and it turns out 2 and is equal to 1 and is equal to 1 2
00:27:46
the output for a is equal to 1 2 we will have
00:27:56
single root matching x 1 kg
00:27:58
the old ones are falling off the roots are falling off now
00:28:04
let's see at what and how much
00:28:07
roots and what kind of roots we will arrange
00:28:09
large number line a
00:28:19
at
00:28:20
and greater than 0x 1 is essentially a root
00:28:24
equation for a from 0 to 1 2 x 2 is
00:28:27
root of the equation for a 1 2
00:28:29
they match, that is, you need to apply
00:28:32
zero one second is just not enough
00:28:35
usually more, that is, we apply a zero and
00:28:39
1 2 and now we will watch everything
00:28:46
at what and how many roots and what kind of roots
00:28:49
and so we consider the situation when a
00:28:56
less than zero when a is from 0 to
00:28:59
when a is 0 when a is from 0 to 1 2
00:29:05
when a is exactly 2 and when a is greater than
00:29:08
1 2 so if a is less than zero then x 1
00:29:13
is the root
00:29:14
if a is less than 0 no expert is
00:29:18
root when a is greater than 0, that is, x 1 is not
00:29:20
aek 2 is the root
00:29:22
x 2 is the root of 0 to 1 2
00:29:25
inclusive, that is, there are no roots here
00:29:31
equals 0 is a root even more precisely when
00:29:35
and equals 0 x 1 is the root no it
00:29:38
is a root for a greater than 0 and x 2
00:29:41
is the root to x 2 is equal to 1 minus 2 a
00:29:47
at from 0 to 1 2 inclusive
00:29:50
if a is equal to zero then it turns out x 2
00:29:53
the only root of
00:29:57
equals 0 circle and equals 0 does not fit
00:29:59
if from 0 to 1 2 segment from 0 to 1 2
00:30:03
enter into greater than zero up to therefore x 1
00:30:08
equal to zero exists here, that is
00:30:11
is the root of the equation and the interval
00:30:15
from 0 to 1 2 are included in the segment from 0 to for
00:30:17
the second one is of course therefore x 2 is equal to 1 here
00:30:22
minus 2 and the roots are definitely not
00:30:25
coincide because they do not coincide at 1
00:30:27
2
00:30:28
that's why we have two different roots here
00:30:30
we feed two different things, I don’t need it, we don’t need it
00:30:32
they are needed in such a way that there will be two
00:30:35
times by roots if a is equal to 1 2
00:30:39
if a is equal to 2 then x 1 will be
00:30:43
root of the equation for a greater than 0 and x 1
00:30:45
will be equal to zero x 2 will be equal to
00:30:53
equals 1 2
00:30:54
it will be equal to 1 minus 2 but it too
00:30:56
there is a square bracket here yes that's why he
00:30:58
is also the root of equation 1 -2 a
00:31:01
if a equals 1 2 it turns out 0 that is, y
00:31:05
we have two roots but they coincide
00:31:07
2 matching roots 2 matching roots
00:31:20
so a equals 1 2 will be the answer
00:31:22
further if a is more than 1 2
00:31:25
if a is greater than 0 then x 1 will be
00:31:28
the root of the equation, that is, here x 1 is equal to
00:31:29
zero and which
00:31:33
but it is not the root of the equation for a
00:31:35
more than her 2 so only one
00:31:38
the root turns out to be Tokyo, everything suits us
00:31:40
we write the answer and it suits us
00:31:46
equal to zero and a from 1 2 to plus
00:31:52
let's run through everything for infinity
00:31:55
the solution initially has a square equal to
00:31:58
how to solve a square, write down the difference
00:32:01
squares, that is, we square to the right
00:32:03
we transfer to the left
00:32:04
difference of squares a minus b times plus b
00:32:08
we simplify and the product is equal to
00:32:10
zero plus 1 plus x must be from zero
00:32:13
to one when the product is zero
00:32:16
when at least one of the factors is 0
00:32:17
plus 1 plus x from zero to one in short
00:32:20
we find the roots 0 and 1 -2 + a to z plus
00:32:23
x from zero to one we need so that from
00:32:25
two roots only one knife left
00:32:28
need to find when there is only one
00:32:30
root x 1 is a root for these
00:32:33
and x 2 is a root for such
00:32:36
and from 0 to 1 2
00:32:38
but they coincide with this and
00:32:42
and we applied everything and looked at what
00:32:45
A x 1 will exist for what a
00:32:49
x 2 would exist and circle these
00:32:51
situations when we either have one root
00:32:53
or two roots but coinciding
00:32:56
it turned out that with these
00:32:58
and in the answer we have only one root
00:33:04
the second solution is analytical
00:33:07
the first one was graphic now
00:33:09
analytically, well, let’s do that too
00:33:11
on the right let's move it to the left to take it out
00:33:14
en masse, that is, it turns out
00:33:17
rewrite the left side minus 5x minus
00:33:28
2 l n 2 x minus and all this is equal to zero
00:33:35
put 5x minus 2 out of brackets and
00:33:39
stays with us
00:33:40
in brackets l n minus
00:33:43
l.n.
00:33:51
so when the product is equal to zero when
00:33:54
at least one of the factors is zero and
00:33:56
the second one exists, that is, it is necessary that
00:34:01
each of them was equal to zero and
00:34:04
to be carried out indicate roughly speaking
00:34:06
that is, we say that 5x minus 2
00:34:09
must be equal to zero 2 bracket too
00:34:12
must be zero
00:34:22
in this case, the decrees x plus must be followed
00:34:25
a must be greater than 0 2 x minus a
00:34:28
must be greater than 0 and
00:34:31
x must be between zero and
00:34:33
units let's solve these two
00:34:39
elementary equations it turns out
00:34:45
two to the right 2 divided by 5 x equals 0.4
00:34:50
this is the first root
00:34:51
second root how to find l n right and
00:34:55
remove logarithms
00:34:57
that is, x + a is equal to 2 x minus a and k
00:35:05
pluses we rewrite more than 0 twos with
00:35:08
minus greater than 0x from zero to one
00:35:11
inclusive then we express x 2 now
00:35:14
let's find it turns out x 1 equals 0 integers
00:35:19
four tenths and xyg to the right and left and to
00:35:27
2 equals 2a
00:35:28
that is, we have two roots 1 2 and both of them
00:35:31
should be deleted well no stop now
00:35:36
I want to say that they both should
00:35:37
satisfy dc or be in range from
00:35:41
zero to one see if they are both
00:35:43
satisfy there for
00:35:44
and are in the interval from zero to one
00:35:45
then we have about two roots
00:35:51
it is necessary that exactly one of them
00:35:53
satisfied dzy was in the segment
00:35:55
parent is exactly 1 and the second is not or
00:35:59
on the contrary 1 was 2 was not or vice versa 1
00:36:02
wasn't the second was or
00:36:04
so that they coincide with each other, that is
00:36:06
there seem to be three cases here, well, about
00:36:10
coincidence and we'll talk at the end
00:36:12
let's find out x 1 suitable for what
00:36:15
and that is, when he satisfies there for
00:36:18
and when it is in the range from zero to one
00:36:19
and to the second at what a satisfying
00:36:22
there for her from zero to one and when
00:36:24
they match we'll see in the end
00:36:26
shorter shorter
00:36:30
x 1 is equal to 0.4 when at a
00:36:38
satisfying it turns out about the dose
00:36:43
that is, satisfying all this
00:36:46
well x is from zero to one but not from
00:36:48
zero to one, that is, roughly speaking, a
00:36:50
must satisfy two inequalities x
00:36:52
plus a is greater than 0 and 2 x minus a must
00:36:57
be greater than 0
00:36:58
substitute x equals 0 4 tenths
00:37:01
it turns out 0 4 + and more than 0 2 multiply
00:37:07
by 0 4 minus and more than 0 that is, we
00:37:11
Now we’ll find out at what a x 1 will be
00:37:13
a good root which is a good root
00:37:16
the equation will generally be more than -04
00:37:18
and less than 08 output therefore when
00:37:24
and with the proper from so it is 08 and so
00:37:30
-04 to 0 8 x 1 will only be
00:37:40
with these
00:37:41
and x 1 will be the root of the equation
00:37:45
in front of others and he is there, violating the recording there
00:37:49
is not a root of the equation x 1 will be
00:37:51
to be a root of the equation means when
00:38:00
and from minus 0 4 to 8 x 2 at what a
00:38:05
x 2 it is equal to 2 and so it will be
00:38:10
be the root of the equation for a
00:38:12
satisfying dzi also he must
00:38:18
get into the interval from zero to one here
00:38:20
with him not everything is so obvious if 04
00:38:22
clearly included in the interval from zero to
00:38:23
units up to 2 but just take some
00:38:26
but they enter, that is, this root must
00:38:29
satisfy y dc that is x plus a
00:38:31
greater than 0 must be 2 x minus a must
00:38:33
be greater than 0 and it must fit into
00:38:37
segment from zero to one
00:38:41
it turns out that under x we ​​substitute 2 a 2a + a
00:38:46
greater than zero under x we ​​substitute 2 that is
00:38:50
two by two a
00:38:53
minus greater than zero under x we ​​substitute
00:38:59
a210 in the end I couldn’t choose for me
00:39:03
write x or two but let’s do it anyway
00:39:06
We’ll probably leave x here and substitute it here
00:39:15
2 and it turns out from zero to one should
00:39:17
be solved to understand at what a x 2
00:39:22
will be a suitable root so it turns out 3
00:39:25
and more than 0
00:39:26
from which it follows that a is greater than 0 3 a
00:39:30
more than 0 5 and more than 0 follows here on
00:39:33
multiply one second, everything turns out and from
00:39:37
0 to 1 2 it turns out that at
00:39:43
but from zero, empty is still more important.
00:39:50
for a from 0 to 1 2 square bracket here
00:39:55
with these
00:39:56
and x is second
00:39:59
will be the root of the equation
00:40:06
also write separately at what a roots
00:40:12
match
00:40:13
but we can see it a little later let's
00:40:19
let's now say that x1 coincides with
00:40:24
x sex 2 when if what if so x 1
00:40:32
we have 0.4
00:40:33
equal to the old 2 and that is, if a
00:40:38
equals 0 4 divided by 2023 a
00:40:42
equals 0 2 roots coincide
00:40:47
Yes, after all, on the number line we would have it
00:40:50
didn't see it so it's definitely here
00:40:52
write x 1 matches to old
00:40:54
because we have a equal to 0 2 nowhere yet
00:40:56
this has not been noticed before
00:40:58
information yes that's what x 1 matches
00:41:00
with to old with this and this is important
00:41:02
now let's go to the number line
00:41:05
let's apply everything we know and see
00:41:11
at what and how many roots
00:41:12
number line and the first root
00:41:16
is the root of minus 0 4 to 08 then
00:41:19
there we apply minus 0 4 tenths we
00:41:26
apply 0.8 zero one second and 02 like this
00:41:33
that is, the next zero is 0 2 1 2
00:41:45
painted over again, just a dash like that
00:41:49
0 0 5 1 2 0 5 and 08 it was still like that now
00:41:57
we'll see at what and how long
00:42:00
we'll get roots, well that's who I am
00:42:02
I usually draw lines you can like how
00:42:04
if you want to do it differently there, I’ll do it like this
00:42:07
I do the usual purely for myself and so if
00:42:13
let's first consider the situation if
00:42:16
and less than -04 then what if a
00:42:19
exactly, exactly -04 what will happen if a from
00:42:24
-04 to zero then what if a is equal to 0 then what
00:42:29
will be if a from 0 to 0 2 then what
00:42:33
how many roots will occur if a is exactly 0
00:42:35
2 then how many roots if a is from 0 2 to 0 5
00:42:39
then how many roots if a is exactly 0 5 then
00:42:42
how many roots if a is from 05 to 08 then
00:42:46
how many roots if a is 08 then
00:42:49
how many roots if a is greater than 08?
00:42:51
how many roots let's give it all
00:42:52
analyze
00:42:53
so if a is less than -04 then the first
00:42:58
root and is a suitable second
00:43:02
the root too, that is, it’s simply not here
00:43:06
roots
00:43:09
if a is exactly 04 minutes
00:43:12
exactly -04 then the first root is not
00:43:15
the second one is also suitable if a between -04
00:43:25
and zero then the first root is
00:43:29
suitable and it is equal to 0 4 that is, here x
00:43:33
1 is equal to 0.4 and x 2 x 2 appears only
00:43:39
from 0 to 1 2 that is x 2 not yet means
00:43:42
at and from -04 to zero we have one root like this
00:43:46
and we are satisfied
00:43:48
if a is equal to 0 to 1 the root exists and
00:43:52
it is equal to 0.4
00:43:57
if a is 0 then 2 roots do not exist
00:44:01
because it exists from 0 to 1 2
00:44:03
inclusive therefore a exactly zero me
00:44:06
also satisfied with the answer and will move on
00:44:08
if a is from 0 to 0 2 then the first root is there
00:44:14
exists and is equal to 0.4 and the second root
00:44:20
the second root for 0 to 0 2 exists
00:44:25
from 0 to 0 2 is included in the segment but in
00:44:27
interval from 0 to 1 2 and the root will be
00:44:30
is equal to 2 x 2 will be equal to 2 and that is
00:44:35
will change all the time if and equals
00:44:37
0.1 then it will be 2 multiplied by 0 1 but obviously
00:44:40
they won't match because they will match
00:44:42
at 0 2
00:44:43
when equal to 0 you figured this out earlier
00:44:46
we have two roots to 2
00:44:48
root
00:44:49
I don’t need two minutes until 1, let’s continue
00:44:51
see if a equals 0 2
00:44:54
if a is equal to 0 2 to 1 the root exists
00:44:58
and it is equal to 0.4
00:45:02
if a is equal to 0 2 then the second root
00:45:07
exists and it is equal to what it is equal to 2
00:45:10
multiply by and that is 2 multiplied by 0 2
00:45:13
that is, 0 4 we have, as it were, two roots like
00:45:17
before but now they coincide, that is
00:45:21
we can say that we have one that matches
00:45:22
the root, you understand, that is, and me
00:45:25
already satisfied with one matching root a
00:45:29
equals 0 2
00:45:31
that's good it fits now if a
00:45:35
between 0 2 and 0 5 1 the root exists and it
00:45:41
is equal to 0.4 and the second root
00:45:45
between 0205 also exists and it’s some kind of
00:45:50
the other is just 2 and that means we have two roots
00:45:52
I don't need 2 roots that's not what I need
00:45:56
I'm looking for which will have one root like this
00:46:00
if a is equal to 0 5 to 1 the root exists
00:46:03
and it is equal to 0.4
00:46:07
if a is equal to 0 5 then the second root
00:46:09
exists and it is equal to 2 a but if a
00:46:14
equals 0 5 then 2005 is one and we have
00:46:17
it turns out there are two different roots, I’m not the same
00:46:22
and I'm looking for when there will be two different roots if a
00:46:24
from 05 to 08 then the first root exists
00:46:29
and it is equal to 0.4 and the second root is from 05 to
00:46:35
08 doesn't exist because he
00:46:37
exists up to 0 5 inclusive
00:46:39
everything is missing, that is, we have one root
00:46:42
means such a segment is such an interval
00:46:44
I'm happy if a is exactly zero eight
00:46:48
then 1 roots do not exist and the second one does not exist either
00:46:52
that is, there are no roots at all if a is to the right
00:46:58
than 08 it will also not give roots
00:47:00
friend
00:47:04
that's all that we circled goes in response
00:47:07
there is an answer like this
00:47:10
from minus 0.4
00:47:13
not inclusive up to zero inclusive
00:47:16
then two separate tests
00:47:18
tenths and from 05 to 08 not inclusive
00:47:24
or another problem like this analytically
00:47:29
decided that is, we threw the right one
00:47:31
part to the left to take the total out
00:47:33
bracket and say when the product
00:47:35
equals zero, found two roots 042 and we have
00:47:39
there is the same there is a segment from zero to
00:47:41
units if x 1 satisfies
00:47:44
Judas for her is in the segment then he
00:47:46
suitable if x 2 satisfies there
00:47:50
behind and is in a crack then he
00:47:51
suitable so x 1 suitable for
00:47:54
such a x 2 suitable for such a and
00:47:59
we all do not coincide, they are equal to a equal to 0 2
00:48:03
we put all these on a number
00:48:06
direct and look at what and how much
00:48:08
roots and some roots and circle those
00:48:13
situations where
00:48:14
exactly one root turns out like this
00:48:18
task find all values ​​for each
00:48:22
of which the equation has exactly one
00:48:23
root on the interval from 0 to 3 meaning
00:48:26
the solution is to find
00:48:29
all the roots of the equation are there one two or
00:48:31
three most likely three
00:48:33
here one here two here legs 2 I don’t know
00:48:38
Briefly speaking find all the roots, there are two or three of them and
00:48:42
look at which ones and each of them
00:48:45
is the root of the equation for 3 rows 3 then
00:48:48
is at what and this root
00:48:50
satisfies there for
00:48:51
and is in the segment da trick end well
00:48:54
then see at what and how much
00:48:56
there will be some roots in the stern and
00:48:57
in general, well, where to start is obvious before
00:49:00
product equals zero when when
00:49:01
each of the factors is equal to zero and also
00:49:04
ode for fulfilled yes that is we write
00:49:06
that l.n. 4x minus 1 equals zero or
00:49:12
the second factor is zero
00:49:24
plus under logarithmic should be
00:49:26
greater than 0 plus radical must be
00:49:31
greater than or equal to 0 plus x must be in
00:49:40
segment from 0 to 3 approx. all this is included in the system
00:49:43
you can push it so let's decide two
00:49:47
equations can, in principle, be written directly into
00:49:49
system to solve them and so go in parallel
00:49:51
go to the end yes but you can just do them
00:49:53
decide somewhere separately and then
00:49:56
back to the system let's do this
00:49:57
that is, we have equation 1 equation
00:50:00
2 and we'll deal with them first
00:50:02
equation 1 l n 4x minus 1 equals zero y
00:50:07
natural logarithm in base e we
00:50:10
and raise to the zero power we get
00:50:11
logarithmic and classical
00:50:13
solve the equation, that is, it turns out in
00:50:17
0 equals one is 4x minus 1 one
00:50:23
to the left that is 2 equals 4 x x equals 2
00:50:27
divide by 4 1 2 this is x 1 then the second
00:50:33
equation solve root is zero when
00:50:37
its radical is equal to zero, that is, x
00:50:39
square minus 6 x plus 6x minus a
00:50:45
square equals zero quadratic equations
00:50:47
to equal zero when so well here you can
00:50:53
try it somehow, of course, if it builds
00:50:57
this equation is a circle obvious but
00:50:59
if not build 100 if analytically
00:51:03
you can decide by the discriminant
00:51:05
find roots
00:51:09
through fault, perhaps through fault, too
00:51:12
it seems possible the sum is 6 and the product is 6 and
00:51:15
minus and square, well you can guess
00:51:17
probably but by discriminant probably
00:51:19
it will be easier from the thickness of normal roots
00:51:21
there is a group, I think it’s possible
00:51:23
somehow a group can also be grouped
00:51:24
can be grouped shorter
00:51:26
either by discriminant y or by vieta but
00:51:29
you need a lot of imagination or grouping
00:51:32
let's group shine remnant you
00:51:34
you can through the tap this is coefficient b
00:51:37
this is the coefficient a this coefficient is c
00:51:39
discriminant two roots is xcom 2
00:51:42
3 also 1 is already taken, well, grouping
00:51:45
steeper than x square minus and square is
00:51:48
difference of squares x minus a by x plus a
00:51:51
and from minus 6x plus 6 a can be taken out
00:51:56
minus 6 out of brackets will leave x minus y
00:52:00
equals zero now x minus and we take it out
00:52:03
parentheses and remains x plus and minus 6 when
00:52:09
the product is equal to zero when at least
00:52:11
one factor is zero, that is, x
00:52:12
is equal to and this is x 2 is already and x 3 is equal to
00:52:16
it turns out that well, here it is -6 on the right
00:52:20
reroll and get 6 minus otherwise
00:52:23
there are three roots of us 1 2 3 so let's go back to
00:52:26
system let's go back to the system
00:52:35
we have this kind of system to
00:52:42
x 1 is equal to 1 2 x 2 is equal to and x 3 is equal to 6
00:52:50
minus a and we have three more conditions 4x
00:52:57
minus 1 is greater than 0 well, we can solve this
00:53:00
one to the right and divide x by 4 both sides
00:53:03
more than by 4 so also x square minus
00:53:09
6 x plus 6x minus and the square is greater or
00:53:14
equals 0 and x must be between 0 and 3 in
00:53:19
In principle, you can find the intersection here
00:53:21
there are more than 1 4 of these fixies but
00:53:24
less than or equal to three is obtained
00:53:26
let's simplify it a little let it be
00:53:28
a little simpler, that is, we will get something like this
00:53:31
Well, there will be a little less systems
00:53:34
although it was possible to substitute
00:53:36
leave x 1 equal to 1 2 x 2 equal to a x 3
00:53:41
equals 6 mitus and
00:53:45
x squared minus 6 x + 6 a minus a
00:53:50
square must be greater than or equal to 0 and
00:53:52
x must be that is, we find
00:53:54
suppression more than 1 4 from 0 to 3 x
00:53:57
must be from 1 4 to 3 inclusive all
00:54:01
when x 1 is the root of the equation for
00:54:04
cod when he satisfies dc and
00:54:08
lies in the segment but she lies like that in
00:54:10
segment therefore only when he takes away
00:54:12
y even when x 2 is a root when
00:54:15
he satisfies dc but in general he
00:54:17
will hit the dose because he
00:54:20
obtained from the radical equation equal to
00:54:24
0 so he will definitely hit after us
00:54:26
no big deal, let's check it again
00:54:29
fashion when he lies in the segment in
00:54:31
interval from 1 4 to 3 and when x 3 is
00:54:34
be the root level
00:54:35
when Zeno will be inside there again
00:54:37
from here and when it lies in the segment in
00:54:39
in the interval from 1 4 to 3 another 1 x 1 equals 1
00:54:46
2 when with a satisfying here dz
00:54:54
greater than or equal to 0 well, that’s already x1 4 to
00:54:58
3 but he is already from 1 4 to 3 1 2
00:55:00
between 1 4 three so just water for
00:55:05
must be performed at the same time and jambs
00:55:07
minus 6x plus 6x minus and the square is large
00:55:12
equals 0, substitute the second one under x1
00:55:14
it turns out 1 4 minus 3 plus 6 a minus a
00:55:18
square
00:55:19
greater than or equal to 0, that is, minus a in
00:55:22
squared plus 6x 1 4 minus 3 is minus
00:55:26
11 quarters greater than or equal to 0 let's
00:55:31
We multiply everything by -4, that is, we get 4 a
00:55:38
square minus 24 + 11 less than or equal to 0
00:55:45
it looks kinda bad but ok
00:55:49
discriminant 576 -16 by 11 176 good 20
00:56:00
square equals 24 plus minus 20 divided
00:56:06
by 8, that is, we are on the number line a
00:56:10
We apply that forty four divided by 8 is
00:56:14
five and a half and
00:56:19
4 I'll take them, that is, 0 5 and for the second
00:56:24
Well, let 05 be like this, let’s arrange it like this
00:56:29
intervals plus minus plus signs
00:56:31
we need and for which the value
00:56:34
expressions less than or equal to 0, that is, we
00:56:36
Minsk needs all the dots painted over
00:56:38
these
00:56:39
and x 1 is the root of please and the conclusion
00:56:41
let's do therefore for and for
00:56:45
proper interval from 0 5 to 5 s
00:56:48
half x 1 is the root of the equation
00:56:52
well x 1 is equal to 1 2 but let's put it this way
00:56:56
is the root of the equation on the interval a
00:57:02
at what a
00:57:03
x 2 is the root of the equation let's
00:57:06
let's find out x 2 which is equal to a
00:57:14
is the root of the equation for a
00:57:16
satisfying what requirements
00:57:19
firstly it must be from 1 4 to 3 thousand
00:57:25
x must be between 1 4 and 3 and it must
00:57:29
satisfy u dose to be honest we
00:57:31
we understand that he will definitely satisfy there
00:57:32
for if you don't understand then turn it on
00:57:35
this system won't get any worse
00:57:39
it just won't affect anything
00:57:42
will get well here very easily, that is, under
00:57:44
x and we substitute a must be from 1 4 to
00:57:46
3 and here a we substitute here it will be a
00:57:50
square minus 6x plus 6x minus a square
00:57:53
0 is greater than or equal to 0 for any a output
00:58:00
at
00:58:02
and with proper from 1 4
00:58:05
let's put it in decimals
00:58:07
we write then when an belongs to 0.25 to
00:58:11
3 inclusive x second which is equal to a
00:58:15
will be the root of the equation
00:58:26
so a x 3 which was 6 minus a
00:58:30
is the root of the equation when x 30
00:58:35
equals 6 minus a is the root
00:58:39
equations for
00:58:40
so with a here it was with a,
00:58:42
satisfying for a
00:58:44
, satisfying what requirements
00:58:47
again x must be from 1 4 to 3 and must
00:58:53
be performed ude for but again
00:58:54
since 6 x is equal to 6 minus and we and
00:58:57
got by solving the equation
00:58:59
radical equals 0 then of course it is
00:59:03
satisfies the decrees but if we don't
00:59:05
understood then we write x square minus 6 x +
00:59:10
6 a minus a squared is greater than or equal to 0 c
00:59:13
system and so under x we ​​substitute 6 minus
00:59:15
and from 1 4 to 3 is inclusive
00:59:20
so under x we ​​substitute 6 minus 1 6 minus
00:59:23
and now there will be a lot of tabs to solve at least
00:59:25
obviously everything fits six by six
00:59:27
minus plus 6x minus a square is large
00:59:32
equals 0 subtract 6 from all three sides
00:59:36
double inequality here it turns out
00:59:39
minus a from 1 4 minus 6 minus 5 7 5 3
00:59:46
minus 6 minus 3 open the square
00:59:51
difference 36 minus 12x + a squared minus
00:59:57
3 6 + 6 + 6 a minus a square large
01:00:02
equals 0 equals 0 turns out look 12
01:00:06
12 and in return is destroyed by a square
01:00:08
square is 36 minus 36, that is, on
01:00:12
minus 1 multiply it turns out 5.75 3a
01:00:18
but the icons need to be expanded, that is, because
01:00:21
that we multiply negatively and there will be more
01:00:23
or equal here there will be strictly more output
01:00:28
at
01:00:29
and with proper from 5-7 so from 3
01:00:33
it turns out yes
01:00:36
yes 5.75 not inclusive x 3 which
01:00:41
equals 6 minus a
01:00:43
is the root of the equation on the interval well
01:00:50
for crackling from 0 to 3
01:00:53
now let's see at what a
01:00:55
the roots coincide here x 1 coincides with k
01:00:58
old at what x 1 sex coincides
01:01:04
old if what happens if x 1
01:01:10
equal to and which that is x 1 then we have 1
01:01:13
2 x 2 is equal and here is the output when a is equal to 0.5
01:01:23
x 1
01:01:25
to the rabbi they coincide with the old one
01:01:26
further
01:01:28
x 1 can coincide with ex third if
01:01:35
what happens if x 1 is equal to x third
01:01:40
that is, exactly five and a half conclusion
01:01:45
at exactly five and a half x 1 is equal to x 3
01:01:51
match and x 2 can match sex with
01:01:55
third if x 2 is equal to x third output
01:02:10
when equal to 3 x 2 correct we will meet
01:02:16
now let's see at what a
01:02:17
how many more roots will we have in this time?
01:02:19
roots we construct a large number line a and
01:02:25
we apply everything to it that affects
01:02:29
the number and type of roots means x 1
01:02:33
exists at a from 05 to five s
01:02:36
half x 2 from 0 25 to 3 x 3 from 3 to 5
01:02:43
5 75 hundredths, that is, you need to apply the most
01:02:45
small 025 then 05 then three five s
01:02:48
half and 575
01:02:49
so you need to lead to 025 1
01:02:55
then 05 then three it seems like yes so three
01:03:03
five and a half 575
01:03:08
five and a half and 575 we'll see what
01:03:16
will be if a is less than zero 25 if a
01:03:18
exactly zero 25 if a is from 0 25 to 05
01:03:24
if exactly 0 5 if a from 0 5 to 3
01:03:31
if a is equal to 3 if a is from three to five c
01:03:35
half if a is equal to five and a half if a is from
01:03:39
five and a half to 5.75 if a is equal
01:03:44
5.75 if a is more than 5.75 how much
01:03:49
there will be roots what kind of roots so when
01:03:52
exists x 1 from 0 5 to 5 and a half
01:03:55
inclusive x 1 is equal to 1 2 that is, x is like that
01:04:02
Let's
01:04:03
small dashes
01:04:16
ikos 1 again from 0.5 to 5 and a half
01:04:20
inclusive i.e. x 1 is the root
01:04:23
here and it is equal to 1 2 x 1 is the root
01:04:27
when from 0 5 to 3 when a is equal to 3 x 1
01:04:32
is the root
01:04:33
with a from three to five and a half x 1
01:04:36
is a root of a exactly five c
01:04:38
half it and the root everything from 05 to five
01:04:42
and half inclusive x 1 is
01:04:45
root x 2 when is the root of 0 20
01:04:48
25 acres not inclusive up to 3
01:04:50
inclusive i.e. x 2 is the root
01:04:54
here here here and here from 0 25 not
01:05:05
inclusive up to 3 inclusive and x 3
01:05:08
is the root from 3 inclusive to 5
01:05:10
of 5 not inclusive i.e. x 3 equals 6
01:05:13
minus and here here here
01:05:22
and then at 5.75 it turns out there are no carnies
01:05:30
so look if a is less than 025 then
01:05:33
no roots
01:05:36
if a is exactly 0 25 then there are no roots
01:05:43
If
01:05:44
and exactly 55 then there are no roots if a is greater
01:05:51
than 75 75 then there are no roots so and now
01:05:54
let's see if there's a couple coincidence x
01:05:57
1 coincides with k old when a is equal to 0 5
01:06:00
that is, if a is equal to 0 5 then see x 1
01:06:04
the same as 2, that is, we actually have
01:06:06
there will actually be one root here because
01:06:10
the roots coincided you understand two roots but they
01:06:13
matching so there will be only one
01:06:15
the root means this and that suits me
01:06:17
further when we still have roots there
01:06:20
coincide at equal to five and a half 1 s
01:06:22
the third coincides, that is, if a is exactly
01:06:25
five and a half substitute then the first
01:06:26
meet will coincide and there will be only one
01:06:28
root or 2 matching ones can be written
01:06:30
or just 1 that is exactly five s
01:06:33
half will also respond with the second one
01:06:36
the third coincides with the prior inside
01:06:39
if a is equal to 3 toeic 2 is equal to 3 x 3 is equal
01:06:42
6 minus 3 out of 3
01:06:43
and we have not 3 roots but two because 2 3
01:06:48
the same will be 1 2 and 3 you understand then
01:06:50
there will actually be two roots
01:06:53
we were looking for we were looking for what will happen
01:06:58
exactly one root
01:06:59
so if a is less than 025 there are no roots
01:07:03
if a is exactly 0 25 there are no roots if a is from 0
01:07:06
25 to 0 5 1 root of 2
01:07:08
if a is equal to 0 5 then we have one root
01:07:11
matching x 1 2 1 5 to 3 we have two
01:07:15
we have three different prior roots inside
01:07:18
there are 2 roots left because there are two
01:07:20
coinciding with a from three to five c
01:07:22
half two different roots at exactly
01:07:24
five and a half we have one root at a
01:07:26
from five and a half to 575 we have one
01:07:29
root at again 75 and no more roots
01:07:32
I just had to enter five s here
01:07:34
circled it with half
01:07:35
they are there for five and a half hours of pipes and
01:07:42
this will be the answer, that is, what we
01:07:46
Circled the hour and write the answer like this
01:07:52
from 0.25 not inclusive to 0.5
01:07:58
inclusive and from five and a half
01:08:02
inclusive up to 5.75 not included or
01:08:07
let's go through the entire solution find all
01:08:12
for each of which the equation has
01:08:13
exactly one root on the interval from 0 to 3
01:08:15
when the product is zero when although
01:08:18
one of the factors is equal to zero plus and
01:08:20
we even add plus and say that x is from 0
01:08:21
up to 3 solve each equation worked
01:08:24
3 roots plus 1 plus x and there, well, here we are
01:08:28
crossed x more than one-fourth of 0
01:08:30
to 3 it will be from 1 4 to 3 x 1 will be
01:08:33
be a root if it satisfies y
01:08:36
even if it is in between it
01:08:39
on 4 this is 3 he and so in the interval from a to
01:08:41
4 to 3 means he needs to hit even
01:08:43
he satisfies there for such a
01:08:46
x 2 is a root if it is in between
01:08:50
from a on 4 to 3 January there for that is
01:08:53
with these a
01:08:54
x 3 drive and quietly is the root x 1
01:08:58
coincides with k old when a is equal to 0 5 x
01:09:00
1 coincides with ex third about five
01:09:02
I'll meet you and half 2 right inside
01:09:03
then we look at what and how much
01:09:06
we have roots and what kind of roots they are
01:09:08
here it is in the end
01:09:10
circle those a for which it turned out exactly
01:09:13
one root
01:09:16
find all values ​​of a for each of
01:09:19
of which the equation has exactly one
01:09:20
root on the segment from 0 given from what
01:09:22
start right side left with minus
01:09:25
throw take out general find roots on
01:09:28
write the entire review x from 0 to units a
01:09:31
then solve the equation and find x1 x2
01:09:34
maybe x3 and see at what a
01:09:39
x 1 will be the root of the equation at
01:09:41
what a x 2 for which they coincide and
01:09:44
then at the end analyze at what
01:09:46
what kind of roots and how many roots
01:09:49
it will be the end, so let's move this one
01:09:51
which is from right to left with a minus
01:10:08
-16 a minus x by ln x minus
01:10:16
all this is equal to zero, now we add l.n.
01:10:19
general
01:10:20
outside the bracket, that is, l.n. 6 a cons and c
01:10:28
big bracket remains the difference
01:10:29
logarithms 2 x plus 2 minus 2 minus ln x
01:10:39
minus y equals zero when the product
01:10:43
equals zero when at least one of
01:10:45
factors equal to 0 2 exists, that is
01:10:46
we say that lnr 6 and minus x is equal to
01:10:53
zero or the difference of logarithms in is equal to
01:10:58
zero
01:11:06
in this case it must be executed up to z and x
01:11:10
must be from zero to one 36 a
01:11:11
minus x greater than zero other under
01:11:16
logarithmic 2 x plus 2 minus 2 too
01:11:20
greater than zero 6 a minus x greater than zero x
01:11:24
minus a is greater than 0 and x must be from zero
01:11:29
up to one we get such a system
01:11:34
Now we solve the equation both equations
01:11:36
very light, well here we have it
01:11:41
it means yes and we are at zero
01:11:43
degree and raise we get under
01:11:45
logarithmic, that is, it turns out that
01:11:53
it turns out that 6 and minus x is equal to one
01:12:00
here we move ln to the right and remove it
01:12:03
deer
01:12:04
that is, it turns out that 2x plus 2 minus 2
01:12:09
equals x minus a
01:12:12
we also rewrite the doses
01:12:24
x from zero to one now let's
01:12:30
let's express xv to each comparison, that is, x 1
01:12:35
equal to what
01:12:37
x from the right to one to the left, that is, and
01:12:39
sides in places other than 6 and minus 1
01:12:42
it turns out this is x 1 x 2 level what and
01:12:45
as left left would be x 2 x minus x x
01:12:50
and 21 minus two to the right, that is
01:12:54
it turns out x 2 is equal to what minus three plus
01:12:59
two
01:13:00
these are the two roots we have
01:13:03
must be executed until z l36h minus x
01:13:06
greater than 0 2 x plus 2 minus 2 greater than 0 as
01:13:13
long ago it was possible to divide by 2 well
01:13:15
it doesn’t matter x minus a is greater than 0 and x is from zero
01:13:19
up to and including one
01:13:21
Next we need it to work out
01:13:25
one root on the interval from 0 to 1
01:13:28
let's find out at what a x 1 will be
01:13:30
is the root of the equation for segments at
01:13:33
which a x 2 will be a root on
01:13:35
segment from 0 to it when they coincide
01:13:38
and then analyze at what a
01:13:40
how much for roots
01:13:42
in short x 1 is equal to 6 a -1 for what a for
01:13:51
A
01:13:52
satisfying everything even roughly speaking
01:13:57
and from zero to one it should be
01:14:01
that is, what should be in the first 6
01:14:05
and minus x must be greater than 0
01:14:08
Actually, the first equation came from
01:14:12
the fact that 6 and minus x is equal to one then
01:14:14
there is 6 and minus x is greater than zero
01:14:15
runs automatically but nothing
01:14:17
terrible thing, we’ll write it down again so that
01:14:20
don't get confused like that 2 minus 2 is greater than 0
01:14:25
must be satisfied x minus a greater than 0
01:14:28
must be satisfied and x from zero to
01:14:30
units must be fulfilled
01:14:34
let's solve this little system
01:14:37
then we do the same for them great
01:14:42
since we will solve this system well let's
01:14:49
we will substitute 6a -1 s for x
01:14:51
beginning, that is, under x I substitute 6 minus
01:14:56
1 will be 6 and then minus x, that is, minus
01:14:59
6a + 1 must be greater than 0 for any a
01:15:04
it will be greater than zero
01:15:05
further along the dex we substitute 6 a minus 1
01:15:07
that is two
01:15:08
multiplied by 6x minus 1 plus 2 minus 2
01:15:16
bodex substitute 6 a minus 1 minus a
01:15:20
more than zero under x6 and minus 1 turns out
01:15:30
What's in 1 answer and we'll reveal any later
01:15:40
brackets will be 12 a minus 2 plus 2 minus
01:15:47
26 minus and this will be 5a minus 1 more
01:15:56
zero here we add one to everything
01:16:01
all three sides of the double inequality
01:16:03
that is, it turns out 16 a 2 well, any
01:16:11
You don’t have to write it, it doesn’t affect anything
01:16:13
so here 14 and more than 45 and more
01:16:23
one here by 1 6 multiply all three
01:16:28
parts of the double inequality, that is, a from
01:16:32
1 6 to 2 sixths to one third well further
01:16:39
but it turns out to be more than 4 14, that is, than
01:16:43
2 sevenths and more than 1 5
01:16:47
and a from one sixth house 1 3
01:16:52
let's find by intersection
01:17:01
these 3 answers, that is, we are on
01:17:04
number line a
01:17:07
apply this way 2 sevenths 1 5 1 pcs and who
01:17:12
least of all well 1 6 obviously least of all
01:17:23
then comes probably 1 5 t co2 sevenths
01:17:26
almost 2 sims, well 1 5 is two
01:17:29
tenths therefore if we compare the two
01:17:32
tenths and 2 sevenths 2 tens of course
01:17:34
less than 1 5 we have further so but 2
01:17:39
sevenths 1 3 if we compare
01:17:41
Well, there’s a common denominator to find like this
01:17:44
2 sevenths 1 3 common denominator twenty
01:17:47
one additional multiplier of 3 here 76
01:17:52
20 first and 720 first 1 3 big by 3
01:18:01
more but this is a draft
01:18:03
leave how we compare fractions is
01:18:06
for parameters probably for 18 tasks not
01:18:09
it is important to indicate such moments in
01:18:12
solution you can indicate it doesn’t matter so
01:18:14
more than 2 sevenths and more than 1 5 a
01:18:21
in the segment from 1 6 to 1 3 where three
01:18:26
shading there the answer is from two
01:18:28
sevenths to 1 3 output at
01:18:32
and with proper from two sevenths to 1 3
01:18:38
x 1
01:18:40
which is equal to what is 6 and minus 1 will be
01:18:46
be the root of the equation for these a
01:18:49
x 1 will be the root of the equation
01:18:51
know
01:18:59
let's find out at which ones and there will be 2 of them
01:19:01
be the root of the equation
01:19:04
x 2 it is equal to what it was x 2 it was equal to
01:19:10
us minus 3 plus 2 minus 3 plus 2 like us
01:19:20
made out we said x 1 will be
01:19:22
root of the equation for a satisfying
01:19:24
ode launch garden zero to one the same
01:19:27
most x 2 will be the root
01:19:29
equations for a
01:19:32
satisfying a to z plus x from zero to
01:19:35
units so here it is
01:19:39
we have these waters here and here
01:19:42
from 0 to 6 and minus x must be greater than 0
01:19:46
2 x plus 2 to minus 2 must be greater
01:19:51
0 x minus a must be greater than 0 and x
01:19:56
must be between zero and one
01:19:59
substitute x now minus 3 plus 2
01:20:02
and besides at what aek 2 will appear
01:20:04
the root of the equation is 6
01:20:08
multiply by a minus x, that is, minus here
01:20:13
this expression is getting plus 3 minus 2
01:20:17
greater than 0 2 must be multiplied by x, that is, by
01:20:21
minus 3 plus 2 plus 2 minus 2 greater than 0
01:20:28
instead of Mexico we substitute minus 3 plus
01:20:30
2 minus and greater than 0 and x sata minus 3 plus
01:20:39
2 and it should be in double inequality
01:20:42
from zero to one we solve it turns out 6 a
01:20:49
plus 3 and that's 9 and that's more than two here
01:20:54
open the brackets minus 6 plus 4
01:21:02
plus 2 minus 2 more than 0 minus 3 minus a
01:21:09
this is minus 4 to the right, we flip the sides
01:21:13
me in some places that is 4 less than two here
01:21:18
let's subtract -2 from all sides
01:21:20
it turns out minus 2 minus 3 minus 1
01:21:28
divide both sides by 9 and it turns out
01:21:31
more than 2 9 minus 6 plus 2 and this is y
01:21:37
we move minus 4 to the right, it will be 4
01:21:40
and less than 24 minus 2 is 2 and less
01:21:46
than 1 2 well because we will divide by 4
01:21:50
any part so here let's take a minus
01:21:52
one third and multiply both parts
01:21:54
it turns out a 2 3 1 3 icons
01:22:01
unfold
01:22:10
Well, if we divide 4 by 4 less than two
01:22:15
then it will be a less than 1 2 and we are already
01:22:18
we wrote it down, that is, let's find it
01:22:20
intersections we need to find intersections
01:22:30
and more than 2 ninths and more is less
01:22:34
than she 2 and a from 1 3 to two thirds
01:22:41
number line so who is the least 1 3
01:22:49
or 2 ninths 2 ninths is less than
01:22:52
02 even 1 3 is 033
01:22:55
so of course 2 ninths of all 1 3
01:23:01
further
01:23:03
half further and two thirds to the right
01:23:07
everyone there 066
01:23:09
Approximately, we apply more than 2 ninths
01:23:12
a is less than 1 2 and a in the interval from 1 3 to
01:23:21
two thirds where there are three hatches there is the answer
01:23:23
that is, the conclusion for a for the proper one from 1
01:23:30
3 to 1 2 x 2 which is equal to minus 3 plus
01:23:38
2 will be the root of the equation
01:23:54
let's find out at what conditions they
01:23:56
match
01:23:57
x 1 x 2 that is, 6 a -1 must be equated to
01:24:00
minus 3 plus 2 x 1
01:24:04
coincides with the old ones, well, let's do this
01:24:13
if 6 and minus 1 is equal to minus 3 plus 2
01:24:22
when does this happen let's
01:24:24
to the left it turns out 9 and is equal to 3 that is, a
01:24:29
equals 1 3 output when a equals 1 3 x 1
01:24:38
By the way, what is 6 times one?
01:24:41
the third -1 that is x 1 is equal to one as x
01:24:47
2 also if a is equal to 1 3 minus 3 multiplied
01:24:50
by 3 plus 21
01:24:51
so x 1 is equal to 1 as x 2 that is they
01:24:55
coincide, yes we all know at what a
01:24:59
x 1 is the root of the equation for what
01:25:02
and x 2 is the root of the equation and at
01:25:05
which and the roots coincide, that is, it will be
01:25:08
two roots of the equation but identical
01:25:09
therefore there is only one root of the equations in
01:25:11
in the end, let's now give a larger number
01:25:13
Let's construct a straight line on to understand when
01:25:15
what and how many roots and what kind of roots
01:25:19
large number line
01:25:27
which ones affect the number of roots
01:25:32
that is, x 1 is the root of these
01:25:35
A
01:25:36
apply 2 sevenths one third then
01:25:39
one third one second that is two
01:25:41
sevenths one third one second only
01:25:45
that's just them and we apply 2 sevenths
01:25:49
one third and one second
01:26:03
we will consider the situation when a
01:26:05
less than 2 sevenths when a is exactly 2
01:26:08
sevenths when and between 2 sevenths and 1 3
01:26:14
when a is exactly 1 3 when a is between 1 3 and 1
01:26:21
2 and when a is equal to 1 2 and when a is greater
01:26:26
than 1 2
01:26:29
so we make such small sticks if
01:26:41
and less than 2 sevenths does x 1 exist
01:26:44
is it the root of the equation if a
01:26:46
less than 2 sevenths x 1 is the root
01:26:50
the equations are for these
01:26:51
and therefore if less than it is not a root but
01:26:55
x 2 drive such a is the root
01:26:58
equation x is less than two sevenths it is not
01:27:00
root that is, with less two sevenths
01:27:02
there are no roots is when a is equal to 2
01:27:11
sevenths someone root a equals 2
01:27:13
sevenths 2 sevenths are not included here therefore
01:27:17
x 1 is not 2 sevenths are not included here
01:27:20
therefore their sides are not equal
01:27:23
2 sevenths again no roots
01:27:27
if we take a from two sevenths to 1 3
01:27:31
the interval from two sevenths to 1 3 is included
01:27:33
here therefore x 1 is the root that is
01:27:37
x 1 is the root and it is equal to 6 a minus
01:27:40
1 is it a root x 2 is it not
01:27:45
root starting from 1 3 right 1 3 tons 3
01:27:48
given 2 so here it is not yet a root
01:27:51
is and we have only one root
01:27:54
root I’m actually looking for something like this when I’m alone
01:27:56
root if a equals 1 3 then x 1
01:28:02
is the root
01:28:03
to 1 3 is included here means x 1 is
01:28:07
root and it is equal to one
01:28:10
x 1 it is equal to 6 and minus 1
01:28:14
well, when a is equal to 1 3 it turns out to be equal to
01:28:16
unit 1 3 included here included
01:28:21
therefore the old one is also a root
01:28:23
and it is also equal to one x 2 it actually
01:28:27
usually equal to minus 3 plus 2
01:28:28
but when a is equal to 1 3 it is equal to one then
01:28:32
we have, like, two roots
01:28:33
but these are two matching roots so
01:28:37
we get only one root
01:28:38
different, different roots one thing two
01:28:41
coinciding roots therefore such and me
01:28:44
they also suit me in return too
01:28:46
I'll take one third further if a from 1 3
01:28:50
the given 2 is located or the interval from 1 3
01:28:54
to 1 2 here I don't have it here
01:28:56
therefore x 1 no x 1 not the root is found
01:29:00
is the interval from 1 3 given 2 inside here
01:29:02
of course yes that's why
01:29:05
here x 2 will be the drive of these a
01:29:07
x 2 will be the root of the equation
01:29:10
minus 3 plus 2 x 1 there won't be only one
01:29:16
the root suits me, I'm looking for something like this
01:29:18
if a is equal to 1 2 x 1 will be
01:29:22
the root of the equation is that he will never again
01:29:23
won't be the smoking equation he
01:29:25
is the root of the equation only when
01:29:27
these and she is the second one already more and that’s it
01:29:29
the rest will be even more that is x 1
01:29:31
no longer root x 2 no longer either
01:29:34
a root is not a root when equal to 1 2
01:29:37
because it is not inclusive up to 1 2
01:29:40
the root is xtar and
01:29:43
and for a greater than 1 2 it is also not a root
01:29:46
we have no roots here
01:29:49
neither the first nor the second are roots and there are none
01:29:53
corr not everything works out suits us but from
01:29:58
two sevenths to 1 3 1 3 too and from 1 3 to
01:30:02
12
01:30:03
so why should we somehow
01:30:06
separate one third if it
01:30:07
inside the gap that suits us
01:30:11
you see, that is, the answer is two-sevenths
01:30:14
to 1 2 just one third why it
01:30:19
highlight separately if it
01:30:22
if this point also suits us therefore
01:30:24
the answer is about two-sevenths
01:30:29
up to 1 star and go through the entire solution
01:30:36
and so initially what we did we
01:30:41
the right side was moved to the left so that
01:30:43
put general out of brackets put out
01:30:46
the result is the product of two factors
01:30:48
is equal to zero, we equate each to zero
01:30:50
plus yes for hang plus x from zero to
01:30:51
units simplify simplify simplify
01:30:54
we get that we have x 1 there is x 2 and o
01:30:56
d z and k sat zero to one
01:30:58
so x 1 will be the root
01:31:00
equation if it satisfies everyone
01:31:02
restrictions in general to everyone and is from
01:31:05
zero to one we found out what it is
01:31:07
occurs at the following a a 2 7 to 1 3
01:31:10
x 2 will be the root of the equation if
01:31:13
it satisfies all modules
01:31:14
Well, everyone is limited by water and is located from
01:31:17
zero to one we found out what it is
01:31:18
occurs when a from one third is given 2
01:31:22
the roots coincide with each other when a is equal to
01:31:25
1 3 we equated them and understood that it was equal
01:31:27
dendrite they fall off equal to one
01:31:30
then we built a number line
01:31:35
and looked at which roots
01:31:38
there is where there are no roots where there is only 1
01:31:41
root grandfather only 2 so they circled those a
01:31:43
in which we only got one
01:31:45
root home abundance
01:31:47
situation when we have two roots but 2
01:31:49
we only have one matching root
01:31:51
find the root of one
01:31:58
all values ​​for which the equation has
01:32:00
the only solution on the interval from 0 to
01:32:01
3
01:32:03
there are some similarities here to x
01:32:06
square minus 7 could be replaced
01:32:07
but there is still 2 x minus, why change it too
01:32:10
that to no other letter like x
01:32:11
square minus 7 on the mind and 2x minus it in
01:32:14
school
01:32:15
but somehow it’s not a very good idea yet
01:32:18
you know what comes to mind just stupidly
01:32:21
squared in envy and the sum that is
01:32:24
square the sum open on the left and there in
01:32:28
during expansion x square minus 7 in
01:32:29
it will be square and we will destroy them
01:32:32
we will destroy them then the square root is
01:32:36
2x minus and this is to destroy give then
01:32:39
there is clearly enough to reveal
01:32:41
simplify the square of the sum to otherwise we get
01:32:46
equation but we must remember that
01:32:48
radical is greater than or equal to 0 and well
01:32:50
that sharply we have 0 to 3, that is, roughly
01:32:53
speaking of visa we have 2 x minus a
01:32:55
greater than or equal to 0 and here we have the equation
01:32:58
when we decide we need to have roots
01:33:01
equations so that the roots of the equation
01:33:06
satisfied and the DZs lay in the segment well
01:33:10
as it should, not all the roots are necessary
01:33:13
Let's say this equation has three roots
01:33:15
before it is not necessary that all three roots and
01:33:17
satisfied dc and lay on the segment
01:33:20
if this happens we have three roots
01:33:21
and we need to have only one
01:33:24
root, that is, there must be some roots
01:33:26
were suitable and some
01:33:28
inappropriate in short so confused you
01:33:32
let's first simplify the obvious
01:33:34
the first action is x square minus 7
01:33:37
take a bracket here and just a square
01:33:39
write down the amounts just in case
01:33:43
square of the sum in some more such
01:33:45
in non-standard situations, not all people
01:33:47
see that's why I have this formula and 7th grade
01:33:51
Let us remind you that is the square of the sum we
01:33:54
we reveal as follows with us
01:33:56
it turns out x squared minus 7 squared
01:34:01
plus twice the product x square
01:34:05
minus 7 and root of 2 x minus a plus
01:34:10
the square of the second expression that is
01:34:12
square kills root right side
01:34:17
I'll rewrite x squared minus 7 squared plus 2x
01:34:21
minus and you still need it, but it’s not equivalent
01:34:24
transition because we still have a limitation
01:34:26
climbs out of the water for that is, we say
01:34:28
what else is 2x minus and it should be more
01:34:31
or equal to 0, well, everything is in the wall
01:34:33
let's take another segment so that x is from 0 to 3
01:34:35
also here in the system
01:34:39
Let's shove this into a system x
01:34:43
square minus 7 squared x square
01:34:45
minus 7 squared cancels out
01:34:47
and 2x minus a also remains what we have
01:34:51
product equals 0 here is the equation
01:34:54
I also need it to fit under DC
01:34:57
roots, well, as they should, again he said that
01:35:00
if it fits then it's a suitable root
01:35:02
well, that is, it will remain the root of the equation with
01:35:05
it doesn’t fit, it won’t stay, you need to understand
01:35:08
how many roots do we have?
01:35:10
that is, we need to solve this equation 1
01:35:12
if you call him a one-off, but in general she is
01:35:17
it’s easy to solve, we don’t know, we need it
01:35:19
Of course I can write it out separately somehow
01:35:22
I would fall asleep, I decided to give a little more detail
01:35:24
I’ll explain in more detail, that is, equation 1
01:35:26
just a day there can be solved in the fields
01:35:28
or right here in the solution x square minus 7
01:35:32
multiplied by root of 2 x minus a equals
01:35:35
zero when
01:35:38
when the product is zero when although
01:35:41
if one of the factors is zero 2
01:35:45
exists Well, we’ll take care of existence here
01:35:49
2x minus a must be greater than or equal to
01:35:51
0 I at least first roots to roots
01:35:54
I will find that is, two is equal to zero to be not
01:35:56
Maybe this two is clear, it’s a parenthesis
01:35:59
is equal to zero for some exe koch then
01:36:02
is x square minus 7 equals zero
01:36:05
and also the root is equal to zero if
01:36:08
radical equals zero of 2x minus a
01:36:10
equals zero shorter than x squared equals 7
01:36:14
then x is equal to plus or minus the root of 7
01:36:18
and here 2x is equal and that is, x is equal to the author
01:36:24
their
01:36:26
we are solving an equation so we must not
01:36:29
neo express aix we are looking to appoint
01:36:32
excite dex first second let it be
01:36:34
will meet them, that is, let's return to ours
01:36:36
system
01:36:38
back to the system
01:36:46
we solved the equation again, it was possible
01:36:49
we decided to do it all verbally and
01:36:51
understood that we have
01:36:52
and xyg or root of 7
01:36:56
or and xyg minus root of 7
01:36:59
or xyg their author here we have three roots
01:37:04
has equations with 2x minus a
01:37:07
must be greater than or equal to 0 and when
01:37:09
in this case x must be from 0 to 3
01:37:11
we notice that minus the root of 7 is not from
01:37:14
0 to 3 means he just disappears like us
01:37:18
we’ll write this and we’ll write this and note that
01:37:27
x 2 does not belong to the segment from 0 to 3
01:37:41
cod from 0 to 3 and it all disappears
01:37:46
simplicity we get in the system we
01:37:48
it turns out that x 1 is equal to the root of 7 x 3
01:37:53
this is the author of their only two roots
01:37:55
there are still potential yes and 2x minus a
01:37:59
must be greater than or equal to 0 and x
01:38:03
should be from 0 to 3 well you can already do that
01:38:05
don't write on 1 start u let it
01:38:08
will be saved again not wrong
01:38:11
say that x 1 must satisfy o
01:38:14
yes for x 2 too because if they are both
01:38:17
satisfy even then we will have two
01:38:19
This equation has two roots
01:38:22
but we need that there was one root
01:38:24
that is, we need one to satisfy
01:38:26
y yes for and the second one did not satisfy the dose
01:38:28
or the second root and maybe
01:38:29
inappropriate if it is not from 0 to 3 but it is
01:38:31
I'm already telling you another way there
01:38:33
solutions in short how we decide how we
01:38:37
we decide
01:38:38
that is, let's say let's say this x 1
01:38:46
is the root of the equation and it is equal to
01:38:49
root 7 when it is the root
01:38:52
equation equal to root 73
01:38:53
but belongs to but satisfying this one
01:38:57
according to this inequality satisfying here
01:39:03
the fact that he is from zero to three is so
01:39:04
it is clear the root of the seeds is from zero to three
01:39:07
prowess satisfying inequality
01:39:17
2x minus a is greater than or equal to 0
01:39:20
that is, now we will find a for which x
01:39:24
1 will be the root of the equation for
01:39:28
To do this, you need to substitute the root of
01:39:30
7 it turns out to be 2 times the root of 7
01:39:32
minus and greater than or equal to 0 that is
01:39:36
and less than or equal to 2 roots of 7 you
01:39:38
what did we find again if and this
01:39:41
if a is less than or equal to 2 roots of 7
01:39:44
the x 1 is the root of the equation
01:39:47
if a equals I don’t know there is 20 if a-20 then
01:39:53
x 1 will not be a root because x 1 will be
01:39:55
violate the decrees you understand if a less
01:39:58
or equal to 2 roots 7 then x 1 root a
01:40:01
if any is very large
01:40:03
then x is the first to violate there for and he he
01:40:05
disappears
01:40:06
from the number of roots, that is, roots remain
01:40:08
not two but only one I hope you understand
01:40:13
so then the next root x 3 to 2 there
01:40:16
we already forgot about him by x third
01:40:19
secondly, it is the root of the equation
01:40:21
when again for a it is the root
01:40:26
for a satisfying the inequality but also
01:40:30
it must lie in the range from 0 to 3
01:40:32
so satisfying the inequality 2x minus
01:40:42
and the big ones are equal to 0 and x from 0 to 3 that is
01:40:52
he still has to be with you until three
01:40:54
again you can ask why us
01:40:55
they didn’t write here that the root of 7 must
01:40:57
be from 0 to 3 that well, from 0 to 3
01:40:59
and the author of them can be from 0 to 3 maybe
01:41:02
not from zero to three you need to understand
01:41:04
at what and he satisfies there and
01:41:07
from 0 to 3 that is here
01:41:10
if here we just substituted the root
01:41:13
out of 7 in Odessa, then in this case we
01:41:16
that means we substitute in dc here too
01:41:21
we substitute that is 2
01:41:23
the author of their minus is greater than or equal to 0 and
01:41:27
their author must be from 0 to 3 that is
01:41:32
we will understand at what a
01:41:34
x the third root of the equation is a
01:41:39
minus and greater than or equal to 0 that is
01:41:43
a minus a is 0 and greater than or equal to 0
01:41:47
I understand that we will need 0 but
01:41:49
Now I’ll explain why I wrote it like that
01:41:51
let's multiply by 2, it turns out from 0 to
01:41:54
6 0 multiplied by which will be greater or
01:41:59
equals 0 to anything, that is
01:42:02
solution 1 inequality will be a any
01:42:05
solution 2 from 0 to 6
01:42:09
if we find intersections then it will remain
01:42:12
in the general intersection from 0 to 6 again
01:42:16
what does found from 0 to 6 mean?
01:42:20
means that if you have from 0 to 6
01:42:23
for example a is equal to 5 then x 3 will be equal to
01:42:27
5 second two and a half means he
01:42:30
is included in the segment from zero to three it is two
01:42:33
and a half and he doesn't break even if
01:42:37
you have a equals 5 x 3 x is two s
01:42:41
half two by two and a half minus 5
01:42:43
equals zero, that is, under the root is what
01:42:45
maybe it's not even broken, that is
01:42:48
this will also be the root of the equation, but also
01:42:51
since this x 3 will be the root of the equation
01:42:53
only if from 0 to 6
01:42:54
if a is equal to 8 then x 3 will not fit in
01:42:58
segment from 0 to 3 it will be 4 don’t blame
01:43:02
power here, well, Audi for him he always
01:43:06
satisfies vice for any he x 3
01:43:09
satisfies the design with others
01:43:12
except from 0 to 6 it just won’t fit into
01:43:14
segment from 0 to 3 that's what happened yes
01:43:17
what to do with these answers what to do with
01:43:20
with these [ __ ], that is, we understood at what
01:43:25
here at the same time
01:43:26
x 1 is a root for these a x 3
01:43:30
is the root
01:43:31
let's see at what and how much
01:43:34
the roots will be washed and that is what we do
01:43:36
large number line and we put it on
01:43:44
all and all and which interest us
01:43:51
that is, we apply a zero, we apply a six
01:43:57
so 2 roots of 7
01:43:59
this is 2 multiplied by 2 something, yes that is
01:44:03
this is less than 6 2 roots of 7 somewhere here
01:44:06
and the six is ​​to the right of everyone I still want
01:44:15
understand how the roots will coincide at what
01:44:20
and the roots will coincide, that’s what he doesn’t want yet
01:44:22
understand that is, at some a roots
01:44:24
will coincide with us
01:44:27
at what and the roots coincide, let's do it
01:44:33
you know, for some and we will have x 1
01:44:35
kor kor root for some a x 2 will be
01:44:38
root
01:44:39
and at some point the roots coincide, let’s
01:44:42
write let's find a let's find a for which x
01:44:54
1
01:44:55
or we can directly understand this right now
01:44:57
that is, it is not necessary to describe what I
01:44:59
I’m writing, but I’m just hoping, just in case, so we’ll find it
01:45:01
and at which x 1 coincides with to old
01:45:07
matches means we have two identical
01:45:10
root there is only one root and it will be
01:45:13
also approach the answer so coincides with x
01:45:16
2 expert matches sex 2
01:45:17
that is, we need to equate x 1 with x3s x 3 x
01:45:22
1 exchange and x 3 turns out a equals 2
01:45:27
root of 7
01:45:28
if a is equal to 2 roots of 7 yes we have two
01:45:31
root we have x 1 root of 2 but these are roots
01:45:34
they will be the same, you understand
01:45:38
so that means if I take I take something
01:45:45
so often give us small sticks here
01:45:48
let's do this for ourselves if I take a
01:45:56
less than zero if I take something like this
01:45:59
here is less than zero then x 1 is the first x
01:46:01
exists if I take a less than zero and
01:46:04
I will collect a minus 10 x 1 exists at a
01:46:08
less than or equal to 2 roots of 7
01:46:09
that is, x 1 here will be x 1 equal to the root
01:46:14
out of 7 it will be at a less than zero to a x 2
01:46:19
will x 2 exists only when a is from 0
01:46:23
until 6
01:46:25
you know that's why x 2
01:46:27
will not be here and who is not here is good
01:46:30
if a is equal to 0 then we have everything
01:46:33
the only root is this
01:46:35
this suits us well, but less than zero suits us
01:46:37
suits and less than zero suits us
01:46:41
that means yes, good, but if a is equal to 0, then what?
01:46:45
if a is 0 then x 1
01:46:49
exists because if a is less or
01:46:52
equals than 2 roots 7 for example a equals 0
01:46:54
then x 1 is equal to the root of 7 to x 1
01:46:56
exists it turns out if a is equal to 0 then
01:46:59
x 1 is equal to the root of 7
01:47:01
and if a is equal to 0 0 is included in the segment from 0
01:47:07
until 6
01:47:08
if a is equal to 0 then we will substitute
01:47:10
under a zero and x 3 will be equal to 0 and 0 and x
01:47:14
3 equals 0, that is, we have two different roots
01:47:18
when a is equal to 0 we have two different codes
01:47:20
I don't need it, I'm over it
01:47:23
the only root on the segment remember
01:47:25
conditions require only one root
01:47:27
only decision
01:47:28
so now we take a from zero to two
01:47:33
roots 7
01:47:38
take from zero to two roots 7 well
01:47:40
for example, for example, some one
01:47:43
let's take one and if a is equal to 1 then x
01:47:48
1 exists and it is equal to the root of 7
01:47:51
that is, x 1 is equal to the root of 7
01:47:54
if a is equal to 1 then x 2 exists because
01:47:59
that it exists from 0 to 6 and if a
01:48:02
equals 1 x 3 turns out equal to well there 1 2
01:48:07
well, or their author’s main thing is that there won’t be x 3
01:48:12
The root of 7 is also equal here, not like
01:48:17
I said and thought, well, that is, x 3 not
01:48:21
will be equal to the root of 7
01:48:23
because a must then be equal to 2
01:48:26
root of 7 on this interval but cannot
01:48:31
equal to 2 roots of 7
01:48:32
that is, x 3 will be equal to a second but if
01:48:36
a equals 1 to 1 2 if a equals 2 then 2
01:48:38
second but just
01:48:39
x 3 will be equal to a second and x 1 x 3
01:48:44
different roots are different roots now yes
01:48:47
because they are the same only at 2
01:48:49
roots 7 so we have two different roots here
01:48:52
a total of two roots is not for me
01:48:54
I need an answer, I'm looking forward to this if
01:48:57
equals 2 roots of 7
01:49:00
if a is equal to 2 roots of 7
01:49:02
the x 1 exists because he
01:49:06
exists when a is less than or equal to 2
01:49:08
the root of 7 it exists and is equal to the root
01:49:10
of 7 that is, if a is equal to 2 roots of 7
01:49:13
So 1 is equal to the root of 7 x 3 x 3
01:49:19
there are from 0 to 6 and that means we
01:49:23
substitute 2 roots from the family
01:49:25
under a 2 roots of 7 divided by 2
01:49:29
it turns out x 3 is equal to the root of 7 that is
01:49:32
yes we have two roots but here they were different
01:49:35
the roots here were different
01:49:36
and now we get the same roots
01:49:41
identical roots, that is, different
01:49:44
the roots are one thing, you know, we have
01:49:46
coinciding roots that's why it's like that for me
01:49:49
fits
01:49:50
if this one didn’t suit me
01:49:53
gave two different roots, something like this and to me
01:49:56
fits she gives one two identical
01:49:58
root that is one root root 71 y
01:50:01
we are the only root I hope you are
01:50:03
understood so if we take something in between
01:50:06
2 roots of 7 and 6 type 5.9 for example yes
01:50:13
if you take 5.9 then x 1 is no longer all x 1
01:50:17
exists to the left than two roots 7 to the right
01:50:19
it doesn't exist and x 3 exists here that is
01:50:24
here x 3 only exists and it is equal
01:50:26
the author of them, well, drive these and from two roots 7
01:50:30
up to 6 for example 5.9 second like this
01:50:35
the only root exists here
01:50:36
the only root that suits me is
01:50:39
there is and from two roots 7 to 6 is me
01:50:44
very satisfied so if a is equal to 6 then x
01:50:49
1 no longer exists x 1
01:50:51
for such a it no longer exists x 1
01:50:55
there is directly less than or equal to two
01:50:57
root 7a x 2 exists at 0 to 6
01:51:02
means x 3 x 2 x 3 x 3 means equal to what
01:51:06
if a is equal to 6 then on the second 6 x 3 is equal
01:51:09
three is the only root for a equals 6 y
01:51:13
there are only a few of us again, the only root
01:51:15
but if a is more than 6 then it’s just roots
01:51:19
no and
01:51:21
x 1 no x 3 no that means the only one
01:51:25
the root we got was purchased here
01:51:26
and we write this answer, that is, the answer is
01:51:30
This one suits us, but it's a minus
01:51:34
infinity to 0 and then from two
01:51:38
roots 7 inclusive
01:51:41
up to 6 inclusive the end let's go over
01:51:46
throughout the solution we see the equation and
01:51:49
we notice that if the square of the sum is revealed
01:51:51
that is, the most obvious transformation
01:51:53
do that there is a lot of chop cut by
01:51:56
mutually destroyed
01:51:57
we did it, we got this
01:52:00
equation it has three roots
01:52:01
root of 7 minus root of 7 and their author
01:52:06
but minus the root of 7 is not included in the segment
01:52:09
from 0 to 3 that is, we have 2 roots left
01:52:11
out of 3 we have one missing
01:52:15
dc is a segment from 0 to 3 but
01:52:18
it is wrong to say that both roots must
01:52:20
satisfy o dzy be in the interval from 0
01:52:24
to 3 because if this happens if
01:52:27
both roots satisfy the language and in the segment
01:52:29
until three then we will have two roots and we
01:52:32
we need to have only one left
01:52:33
root that is, we need one of
01:52:35
they fell out or they matched here we are
01:52:40
we say that x 1 will be the root
01:52:43
equation only if it satisfies y
01:52:45
dc and lies in the interval from 0 to 3 but this is also
01:52:48
so it’s clear the roots of the seed but it lies in
01:52:50
segment from 0 to 3, here we substituted
01:52:53
means x is the root of 7 and we realized that when
01:52:55
like this
01:52:56
x 1 is the root of the equation ax3
01:53:00
is the root of the equation if it
01:53:02
satisfies even
01:53:04
and lies in the interval from 0 to 3 it turned out
01:53:07
what satisfies there for him at all
01:53:09
always and in the interval from 0 to 3 lies at
01:53:12
from 0 to 6
01:53:15
then we are on the number line on thoughts
01:53:17
zero two roots 7 and 6 and started
01:53:20
scan if a is less than zero then x 1
01:53:23
is and which is not if a is equal to 0 you have
01:53:29
we have two different roots, I only need 1
01:53:31
the root to remain
01:53:32
if a is from zero to two roots 7 then we have
01:53:35
two different roots here at equal to 0
01:53:38
specific roots root of 7 and 0 and at
01:53:41
from zero to two roots media different roots
01:53:43
always different depending on different
01:53:46
and if a is equal to 2 roots of 7 then we have
01:53:50
roots 2 2 roots but they coincide, that is
01:53:53
only one root is the root of 7 therefore
01:53:55
it doesn't fit there naturally
01:53:57
often people forget this and that’s what they get
01:54:00
there are three out of four points and we
01:54:02
let's get 4 4th floor let's not forget
01:54:04
matching too he is also one
01:54:07
the only root will ultimately give us
01:54:08
if aa two roots 7 to 6 then x 1 is already
01:54:13
no because x 1 drive exists
01:54:14
such a a x 3 will be different all the time
01:54:22
if a is equal to 6t x 1 a is long gone x 3
01:54:25
the only root is equal to three therefore
01:54:27
we need you if a is greater than 6 then x 1
01:54:30
long gone x 3 won't happen either because
01:54:33
that if a is greater than 6 then x 3 will not be
01:54:35
fit into the segment from 0 to 3 that's all of us
01:54:38
we write down the one that suited us like this
01:54:40
task find all values ​​for each
01:54:44
of which the equation has exactly one
01:54:46
root on the interval from 0 to 1
01:54:48
when the product is zero when although
01:54:51
if one of the factors is equal to 0 2
01:54:53
exists that is, we must each
01:54:54
set the multiplier to 0 and plus is indicated
01:54:57
news and plus x from zero to one we will find
01:55:01
roots will be x 1 x 2 x 3 most likely well
01:55:05
here x 1 is equal to 0 25 it’s already clear x 2 and 3
01:55:09
and the third why I say because here
01:55:11
x quadratic equation two roots rather
01:55:13
in total there will be and so we have three roots and we
01:55:15
let's find x 1 for which oh is the answer
01:55:18
is the root at which ayxta swarm
01:55:21
is the root
01:55:23
for which a x 3 is a root then all
01:55:26
and look at the number line at
01:55:29
what kind of roots will the plan be like this
01:55:31
so when the product is equal to zero
01:55:35
ever the root is zero or
01:55:40
l n equals zero
01:55:50
either one or the other but the radical must
01:55:53
be greater than or equal to 0 and right under
01:55:57
logarithmic must be greater than zero
01:55:58
strictly well
01:56:05
x must be in the range from 0 to ones
01:56:09
we get this system
01:56:11
let's solve it and so the root is equal
01:56:15
zero when the radical is equal to zero yes
01:56:17
that means everything is clear there x is equal to 1 4
01:56:26
on its own it's x 1
01:56:28
what's next with the second equation
01:56:32
here e to the base e to the 0th power is equal to
01:56:34
this entire right side, well
01:56:37
logarithmic, more precisely, so I'm at 0
01:56:39
one that is all all friend
01:56:43
rhythmic equals one it turns out like this
01:56:50
at the same time it is necessary that I will do 4x
01:56:55
plus one is greater than 0 and actually
01:56:57
you can solve it, that is, one to the right
01:56:59
reroll 4x large equals 1 and to 4
01:57:03
divide it turns out x is greater than 1 4
01:57:05
should be x squared minus 2 x plus 2
01:57:13
minus and the square must be greater than 0
01:57:16
px must be between zero and one
01:57:21
so with a quadratic equation but here
01:57:24
throw a one to the left and it will be a square
01:57:26
differences
01:57:28
yes, let's look into this separately
01:57:30
equation so as not to rewrite the extra one
01:57:32
since everything else turns out that way
01:57:38
it turns out let's convert the first one
01:57:40
equation x squared minus 2 x plus 2 and
01:57:45
minus one is plus 1 minus a square
01:57:49
equals zero learn x minus 1 squared
01:57:52
minus and squared is equal to zero difference
01:57:56
it turned out squares, well, just reminding you
01:58:02
not everyone sees in complex examples
01:58:05
elementary formulas of different squares
01:58:07
this formula turns into
01:58:10
product of parentheses a minus and plus
01:58:12
that is, x minus 1 minus and by x minus
01:58:18
1 plus y equals 0, so when is the product
01:58:24
equals zero when at least one factor
01:58:25
is equal to zero, that is, x minus 1 minus a
01:58:28
equal to zero
01:58:29
x minus 1 plus a equals zero, that is, x
01:58:33
it turns out 2 is equal to a + 1x it turns out 3
01:58:38
equals minus x plus 1 so we have x 1
01:58:41
x 2 x 3 back to the system
01:58:52
we have x 1 equals 1 4 we have x 2
01:58:59
equal plus one us is x 3 equal
01:59:05
minus a plus 13 roots we need
01:59:10
so that we also have x more and
01:59:15
equal to 4 x square minus 2 x plus
01:59:21
2 minus and the square must be greater than 0 and
01:59:24
x must be between zero and one
01:59:27
Well, that’s the kind of system we have, so let’s do it
01:59:31
we'll find out x 1 for which a is a root
01:59:34
equation x 2 for which a is
01:59:37
root of wounds x 3 for which a is
01:59:39
let's start with the root of the equation at x 1 so x 1
01:59:44
it is equal to 1 4 for what a for a
01:59:50
satisfying the following requirements
01:59:53
firstly x must be greater than or equal to
01:59:56
than 1 4 but he already satisfies this
02:00:00
requirements
02:00:01
x must be from zero to one it is already
02:00:04
satisfies these requirements, the main thing is
02:00:06
what he should do is this, well he should
02:00:10
satisfy this inequality
02:00:12
is understood that is, for a satisfying
02:00:14
inequality x squared minus 2 x plus 2
02:00:19
minus and the square is greater than 0 let's find out
02:00:22
at what and does it fit here so under x1
02:00:25
4 we substitute 1 4 we put this 1 16
02:00:29
minus 2 times 1 4 plus 2 minus a square
02:00:34
is greater than zero, that is, and the square is less than
02:00:38
count 2 minus half
02:00:42
one and a half + 1 16 so one and a half is for example
02:00:50
24 16
02:00:52
+ 1 1625 16 well of course someone
02:00:59
the clock will write nonsense and less than
02:01:01
plus or minus five quarters is complete nonsense
02:01:03
you need to throw 2516 of them to the left and
02:01:07
write the difference of squares that is
02:01:11
a minus five quarters by a plus five
02:01:17
fourth
02:01:19
less than zero number line and plot
02:01:23
minus 5 4 and 5 4 plus minus plus us
02:01:30
need minuses conclusion for these
02:01:35
and x 1 is the root of the equation derivation
02:01:40
with a belonging from minus 5 4 to 5 4
02:01:49
x 1
02:01:50
equal to 1 4 is the root of the equation for
02:01:53
segment
02:02:00
good thing I'm fed up with the old x 2 is a + 1
02:02:04
do the same with him like this x 2
02:02:07
this is a + 1 it is the root of the equation
02:02:12
with a satisfying which
02:02:15
requirements it must be root larger
02:02:19
or equal to than 1 4 he must be he
02:02:28
must eliminate this inequality and
02:02:29
it must be from zero to one then
02:02:32
there are all three requirements here
02:02:33
so that they execute like this x square minus 2
02:02:39
x plus 2 and for x 3 you will also need all this
02:02:43
write more than 0x must be from
02:02:46
zero to one is in principle possible, of course
02:02:49
these ones cross these ones
02:02:51
inequalities in principle but they are like that
02:02:55
easy that everyone can decide like this
02:02:58
it doesn't matter in general so let's mean
02:03:01
decide x must be greater level than
02:03:05
1 4 means a plus one should be
02:03:09
more Iran than her 4 so now
02:03:13
It’s going to take a long time to write, but let’s
02:03:16
let's swap places doesn't matter so x square
02:03:21
minus 2 bodex we substitute a + 1 it turns out a
02:03:25
plus 1 squared minus 2 over x that is
02:03:29
by plus 1 plus 2 minus and the square should
02:03:34
be greater than 0 and a + 1 from zero to one
02:03:39
inclusive
02:03:43
so it turns out that a is greater than 1
02:03:53
4 minus 1 is minus three quarters and so
02:04:00
here minus one from all three sides
02:04:02
double inequality subtract that is from
02:04:04
minus 1 to 0 it turns out, let's do it here
02:04:08
simplify we reveal the square of the sum to us a
02:04:13
square plus 2 plus 1 minus 2 and minus 2
02:04:20
plus 2 minus a square is greater than 0 a
02:04:24
the square is destroyed 2a is also minus two
02:04:28
plus two also one more than 0 always she
02:04:31
by the way it seems that
02:04:34
x 2 x 3 will satisfy this
02:04:36
condition is always well because they are like
02:04:40
the roots are out of the equation where is this thing
02:04:44
was equal to one therefore we and
02:04:47
it turned out that one is more than zero hour one
02:04:49
more than 0 to 1 more than zero in any case
02:04:53
any and all that remains is to find the intersections
02:04:55
means a is greater than or equal to minus three
02:04:57
fourth and it is from minus 1 to 0 that is
02:04:59
What is the conclusion when and when proper from -3
02:05:08
fourth to 0x second which was a +
02:05:15
1 is the root of the equation
02:05:22
on a given segment let's pro x3
02:05:26
let's understand x thirds is minus a + 1 x 3
02:05:33
which is equal to minus a + 1 is
02:05:38
root of the equation for a satisfying
02:05:41
the same requirements as the old one, that is
02:05:43
it is necessary that
02:05:48
x was greater than or equal to 1 4 so that
02:05:53
performed here x square minus 2 x
02:05:58
plus 2 minus a square
02:06:07
more than 0 to further so that x is from
02:06:12
zero to one, such a system is needed
02:06:16
now we solve we solve it turns out minus a
02:06:21
+ 1 must be greater than or equal to it
02:06:23
4 let's switch places
02:06:27
that is, there will be 1 minus a under x
02:06:30
substitute 1 minus and squared minus 2
02:06:34
by 1 minus and plus two minus square
02:06:40
more than 0 and 1 minus and let's do it here
02:06:44
no it doesn't matter
02:06:46
I thought there was a difference no and so and so not
02:06:49
it will be very convenient so we’ll decide one
02:06:54
each
02:06:55
and to the right, that is, a is less than or equal to
02:06:59
one minus 1 4 than three quarters further
02:07:02
open the square and get 1 -2 a +
02:07:08
and the square is minus 2 plus 2x plus 2
02:07:14
so minus and square is greater than zero square
02:07:18
and 2a were destroyed too, there were triplets too
02:07:22
one is greater than zero for any and so and here
02:07:25
subtract ones from all three sides then
02:07:27
is -1 less than or equal to minus a
02:07:30
less than or equal to zero by -1 multiplied
02:07:35
that is, it turns out that a is less than or equal to
02:07:38
than three quarters and a from 1 to 0 but
02:07:44
the icons need to be expanded, that is, from 0 to
02:07:47
1 but less than or equal to three fourths
02:07:50
output at and at proper from zero to
02:07:56
three quarters
02:08:01
icos 3 is the root of the equation for
02:08:05
segment
02:08:16
we found for which a x 1 is a root
02:08:19
on the segment from minus 5 4 to 5 fourths
02:08:22
not inclusive at what a
02:08:23
x 2 is a root on the segment from minus
02:08:26
3 4 to zero and at what a x 3 is
02:08:29
root of levels zero to three-quarters
02:08:31
now let's look at all these and
02:08:35
[music]
02:08:36
Let's see where and how many roots there will be at
02:08:39
different a
02:08:40
number line and by the way, when do they
02:08:44
coincide, this is also important to understand
02:08:45
when they don't match they can match x
02:08:49
first sex old x first sex third
02:08:51
their 2 sex third x 1 matches although we
02:09:00
we can see this directly, actually, come on
02:09:02
let's check in advance x 1 coincides with iq
02:09:05
old if anything but if x 1 is equal to and
02:09:09
which that is if one fourth is
02:09:11
and there is a plus 1 that is, and is equal to when
02:09:15
minus three-fourths then they fall off conclusion
02:09:22
when a is equal to minus 3 4 x 1
02:09:27
matches ex container
02:09:34
x 1 coincides with the third when if what
02:09:42
if x 1 is equal to x third then a
02:09:48
equals 3 4 output when a equals 3 4 x 1
02:09:56
matches x3 teen
02:10:02
and can match x 2 x 3
02:10:12
if a plus 1 is equal to 1 minus a that is 2a
02:10:18
equal to zero
02:10:19
that is, a is equal to zero when a is equal to 0x like this
02:10:23
I'm right when I say that there is 1 minus and we have
02:10:24
was a + 1 before
02:10:28
output when a is equal to 0 x 2 x 3 are the same
02:10:32
when a is equal to 0 x 2 the sex of the third coincides
02:10:37
and so now the number line and we look
02:10:47
at what and how many roots do we have?
02:10:49
it turns out
02:10:52
we are interested in
02:10:54
and which from minus 5 4 to 5 fourths
02:10:58
Firstly
02:11:07
so from minus 5 4 to 5 fourths then
02:11:11
we are interested in minus three-quarters zero
02:11:16
zero and three quarters yes that is us
02:11:23
interested in minus five quarters
02:11:24
and five fourths then we are interested in
02:11:33
minus three quarters and three quarters
02:11:42
There's a zero between them, that's right, nothing is needed
02:11:47
apply as from 1 means again from
02:11:50
minus 5 4 to 5 4 a bit old minus 3 4
02:11:53
0 from 0 to 3 4 that is, we will consider
02:11:57
situation when a is less than -5 fourths
02:12:00
and let's see how much exicosis we have
02:12:03
situation when a is exactly minus five
02:12:05
let's see how many fourths we have
02:12:06
evsikov when and from minus five fourths
02:12:09
to minus 3 3 4
02:12:12
then a exactly - three three quarters when
02:12:16
and from -3 quarters to zero when equal
02:12:20
zero when from zero to three-quarters
02:12:23
when is equal to three quarters when a is from
02:12:28
three quarters and five quarters
02:12:30
when it's exactly five quarters
02:12:33
when a is more than 4 so if a
02:12:38
less than -5 quarters give and stick
02:12:41
we'll do more
02:12:53
if a is less than -5 4 x 1 is
02:12:57
the root x 1 is the root only of
02:13:01
minus 5 4 to 5 4 that is, not yet
02:13:04
is x 2 is the root of x 2
02:13:10
is a root for such
02:13:12
and that is, it is not yet x 3
02:13:15
is a root in general for positive
02:13:18
not yet, that is, not here
02:13:20
the roots are just, well, minus five
02:13:26
the fourth ones also have no roots there ikos 1 yet
02:13:28
didn't appear but x 1 in short here we have
02:13:33
here is from minus 5 4 to 5 4
02:13:35
in principle we can say that x 1
02:13:37
equals 1 4 here x 1 equals 1 4 here x 1
02:13:49
equals 1 4 here x 1 equals 1 4 here x 1
02:13:56
equals 1 4 here x 1 equals 1 4 here x 1
02:14:04
equals 1 4 here x 1
02:14:07
he's just from minus 5 4 to 5 fourths
02:14:09
all the time there is like a root you understand like this
02:14:13
that sex with old x 2 is the root of
02:14:16
minus 3 4 0 from minus 3 4 include but to
02:14:19
zero, that is, x 2 is the root here
02:14:24
equals a + 1 to 3 4 inclusive that is
02:14:27
x 2 is also a root here x 2
02:14:32
is also a root here x 2 is
02:14:34
root also here and here a x 3
02:14:41
is the root oh no x 2 was
02:14:47
root from minus 3 4 0 to 0 to 0
02:14:52
inclusive
02:14:55
and x 3 is the root of zero to three
02:14:59
fourths from 0 inclusive to 3 4 then
02:15:01
there is x 3 equals 1 minus and x 3 equals 1
02:15:06
minus a
02:15:07
x 3 equals 1 minus so let's do it
02:15:13
let's see where our roots coincide at
02:15:17
minus three fourths are matching
02:15:21
roots because if a minus 3 4 who
02:15:24
here there will be 1 4 that is, we have two here
02:15:29
roots but 2 matching roots that is we
02:15:37
circle the situation when we have x equal to 1 4
02:15:40
the only root for such and we
02:15:43
circle minus three quarters because
02:15:46
there are two of us matching aft, that is, one
02:15:47
the root is the farthest our roots are
02:15:51
coincided when prearo inside the fourth
02:15:56
if you wipe 4 put it will be 1 4 then
02:15:59
we have two matching roots again
02:16:07
three quarters a equals 3 4 circle
02:16:10
Next we circle from three quarters to 5
02:16:13
fourth because there is only one here
02:16:15
root
02:16:17
so it turns out there are no roots here
02:16:22
roots and still feeding, they served and
02:16:27
equals zero that is, if a equals zero then
02:16:29
there are one fourth of us, then one
02:16:33
and one, that is, we have x 2 x 3
02:16:36
matches x 1 other that is, we have like
02:16:39
3 roots
02:16:40
but these two coincide, that is, only two
02:16:42
roots here you understand 3 roots but 2
02:16:45
coincide therefore we are twice aft
02:16:47
and we don’t circle the zero and we don’t take the answer
02:16:49
It’s clear that in response we only take what I
02:16:54
I circled it now so the answer is from
02:16:59
minus 5 4 to minus 3 4 inclusive and from
02:17:07
three quarters inclusive up to 5
02:17:11
fourths not to be included or let's go over
02:17:13
the entire solution product is zero
02:17:17
when when at least one of the factors
02:17:19
equal to zero that is, when 1 equals zero 2
02:17:22
I also love to curtain the garden plus x from
02:17:24
zero to one well the first equation
02:17:27
elementary x is 1 4 and second
02:17:29
the equation
02:17:30
well, also light and to the 0th degree equals under
02:17:32
logarithmic we are a little bit with it
02:17:36
we worked and realized that it gives us two
02:17:38
root a + 1 m amine one minus on so y
02:17:41
us
02:17:42
the original equation gave 3 roots plus
02:17:45
there is 1 plus x from 0 to one x 1
02:17:48
is the root of the equation if it is greater
02:17:51
Iran than 1 4 but so much bigger than it
02:17:53
4 if it is from zero to one, well, from
02:17:55
zero to one means it just has to be
02:17:57
this restriction is fulfilled and that's it
02:18:00
executed under attack h x 2 is
02:18:03
root if it is greater than or equal to it
02:18:05
4 if there is more than 0 under the logarithmic
02:18:08
if x is from zero to one with these
02:18:10
aig 2 is the root
02:18:12
x 3 should also be big before we
02:18:15
by 4 lie in the interval from 0 to 1
02:18:17
it should be logarithmic
02:18:18
greater than 0 with these a x 3 is
02:18:21
the root of the equation x 1 coincides with k
02:18:24
old means we need to equate them with
02:18:26
so x 1 coincides with x third right here
02:18:29
such x 2 coincides with them we will meet at a
02:18:31
like this and we put it on the numerical
02:18:37
direct and all and affecting the quantity
02:18:40
roots and look at what and how many
02:18:43
there will be roots
02:18:44
and circle those situations when we have one
02:18:46
the root turned out in the end
02:18:47
for example, when two matching roots are
02:18:50
after all, one curia here we have 3 roots but
02:18:52
two of them coincided and only two roots
02:18:54
We don't need such situations, we need them
02:18:56
feed the situation when we have one root
02:18:58
or 2 falling ones, that is, 1 or 2
02:19:02
falling here, not that there is one or here
02:19:04
one just x 1 with such a
02:19:07
it turns out that we will have one root
02:19:11
find all values ​​of a for each of
02:19:14
of which the equation has exactly one
02:19:15
root on the interval from 0 to 1
02:19:17
let's factorize the right
02:19:20
radical and 0 it is clear how to decompose into
02:19:24
the factors there are x minus 1 x plus a
02:19:25
In short, in general, if the root is equal to the root then
02:19:28
you can simply equate radicals
02:19:31
question, why did the roots give us the conditions?
02:19:34
Well, let us write more about the dose
02:19:36
in addition, everything is so that we
02:19:38
wrote the radical greater than or equal to 0
02:19:40
by the way, if the root is equal to the root and one
02:19:42
radical we wrote that they are big
02:19:44
equal to 0 2 automatic something equal to
02:19:46
Karina, in short, in short, we need to simplify
02:19:50
simplify the right-hand side by decomposing it into
02:19:53
multipliers either by discriminant or with
02:19:55
using describing and either using
02:19:56
Vieta's theorems
02:19:57
let me show you so let's do it like this
02:20:02
let's break it down
02:20:07
and then we’ll start solving by decomposing
02:20:09
radical of the right side of the equation on
02:20:16
multipliers
02:20:30
Well, you and I remember the decomposition formula
02:20:32
by factors here she is she is x minus x
02:20:40
one for x minus x 2 that is by
02:20:42
discriminant or fault then can be found
02:20:44
roots and substitute into this formula and
02:20:47
there will be factorization then
02:20:48
there is a product of brackets and here
02:20:50
we will add parentheses in that
02:20:51
there to simplify so let's use
02:20:56
I'll show you the discriminant first
02:20:58
with the help, well, it’s enough to solve one
02:21:01
way I'll just show you both
02:21:04
using discriminant as using
02:21:11
discriminant means we rewrite it
02:21:14
3 square minus 3 plus 1 times x +
02:21:21
poll roots we also substitute everything there
02:21:22
under the form so the discriminant is equal to what b
02:21:26
squared, that is, the coefficient ancestor c
02:21:28
square
02:21:29
the square will kill this minus, it turns out 3a
02:21:32
plus 1 squared minus 4 times a
02:21:36
on 3 and on c on a so it turns out on 9 a
02:21:43
square plus 6x plus 1 minus 12 otherwise
02:21:48
there will be 9a square minus 6x plus 1 then
02:21:52
there is this 3a minus 1 squared
02:21:58
find x first second by discriminant
02:22:02
this turns out to be minus b, that is, 3a plus 1
02:22:06
plus minus the root of the expression in
02:22:09
squared root of squared expression
02:22:11
this is the module divided by 2a, that is, by 2
02:22:17
multiply by 3 by 6 modulus is the same
02:22:22
the most that is 3a minus 1 plus minus that is
02:22:24
this is plus minus 3a minus 1 module this is
02:22:26
from a plus expression with a minus and then again
02:22:28
plus minus in short we will have two cases
02:22:31
when we add 3a to 3a plus one
02:22:35
minus 1 and when we subtract 3a minus 1
02:22:37
group
02:22:38
cooking that is, that is, x the first is equal to 3
02:22:43
plus 1 plus 3a minus 1 sixths x 2 is c
02:22:49
minus or when we change signs
02:22:54
minus 3 plus 1 sixths so here are ones
02:22:58
mutually cancel 6 separate by 6
02:23:00
will be and here will be from rub 1 3 here
02:23:11
we found the roots using the discriminant
02:23:13
it was possible to find the roots using the theorem
02:23:16
Vieta using Vieta's theorem
02:23:25
Vieta's theorem states that
02:23:27
the sum of the roots is equal to minus b divided by a
02:23:31
that is, equal to minus this coefficient
02:23:34
divide by three
02:23:38
this is 3a plus one third a product
02:23:45
roots equal to t and divided by a that is, from
02:23:49
third it would seem to pick up the roots
02:23:53
very difficult let's divide 3 term by term
02:23:56
and at 3 it will be
02:23:57
and one by three is one third
02:24:00
and we think so and the sum of what numbers is a +
02:24:05
1 3 if the product of a third well a
02:24:09
and 1 3 actually that is, you can go to the roots
02:24:12
it was easier due to that fault to guess to x 1
02:24:15
this is a and castoro this is 1 3 good
02:24:18
factorization what are we talking about?
02:24:19
says that we first write the coefficient
02:24:23
and that is a three
02:24:25
Next comes the bracket x minus 1 root and
02:24:30
parenthesis x minus 2 root but three
02:24:34
can be thrown into one of the brackets and into
02:24:36
the second one is better x minus a
02:24:39
multiply by 3 x minus 1 that's how we do it
02:24:44
laid out
02:24:45
this is broken down into a multiplier
02:24:48
quadratic trinomial factored like this
02:24:50
let's rewrite what we got
02:24:54
Let's go back to the original equation
02:24:56
there is how we transformed it in general
02:24:59
everything could have been done in the fields like this
02:25:01
Well, it’s probably better to show such things like this
02:25:03
We'll get back to the official decision anyway.
02:25:05
showed him one of the ways to vieta
02:25:07
would show let's go back to the original
02:25:10
equation so to the original equation
02:25:21
means root x squared minus a
02:25:27
the square is equal to the root of and change as we do
02:25:31
there we simplified we simplified by bracket x
02:25:34
minus a and by bracket 3x minus one
02:25:39
root equals root
02:25:41
root equals root let's left left
02:25:44
Let’s also factorize it and it turns out x
02:25:47
minus a by x + a is equal to the root of x minus
02:25:54
and at 3x minus 1 when the root is equal to the root
02:25:58
you can just stupidly equate radicals
02:26:00
the advantages of writing about even memory, that is
02:26:03
this equation is equivalent
02:26:06
it turns out equivalently
02:26:11
equality of radicals
02:26:22
the only thing you need to write about is oh yes for
02:26:25
this radical
02:26:26
x square minus and square is greater or
02:26:29
equals 0, should I write what is the second?
02:26:31
radical is also greater than or equal to 0 no
02:26:34
because we wrote that they are equal
02:26:36
so if the first is greater than or equal to 0 2
02:26:38
automatically large equals 0 here's another x
02:26:41
must be on the range from 0 to ones
02:26:43
let's also write it into the system here
02:26:44
this is how it turns out to be a system for how to solve
02:26:49
equation well let's see what's on the right
02:26:51
to the left with a minus and put a bracket behind
02:26:52
the parenthesis turns out to be x minus and in short here
02:26:59
minus and plains okay I will detail
02:27:01
write x minus a by x plus a minus x
02:27:08
minus and by 3x minus 1 is equal to zero
02:27:13
here z and x from 0 to one should be
02:27:19
Now we put the bracket outside the bracket styx
02:27:23
cons we carry remains
02:27:26
x plus and minus this is buying up, that is
02:27:30
minus 3x + 1 x square minus x square
02:27:35
greater than or equal to 0 xor 0 to one
02:27:40
this is how it turns out to be a system that is before us
02:27:43
when the product is zero when although
02:27:46
if one of the set 0 2 exists then
02:27:48
is we get the totality from us either
02:27:51
1 bracket is equal to zero or 2 brackets
02:27:54
is equal to zero and there is even x from
02:28:02
zero to one
02:28:06
so let's x 1 x to ruin
02:28:09
let's express x 1 equals what the error to the right and to
02:28:14
2 is equal to what, well, we need to solve the equation
02:28:19
here we are and slice xx to the right
02:28:22
there will be 2x equals a + 1 to if 3x and
02:28:27
minus x reroll it will be on the right 2x
02:28:30
on the left a + 1 then x equals a + 1 second
02:28:34
understand yes a + 1 second x is equal to a + 1
02:28:38
second x is equal to a + 1 second but this is
02:28:46
we solved this equation
02:28:48
or let’s divide it term by term, it turns out
02:28:50
half a + 1 2 might be easier this way
02:28:55
will substitute further
02:28:56
x square minus and square is greater or
02:28:59
equal to 0 x must be between zero and one
02:29:01
and so we have two roots if the first root
02:29:08
satisfies there for
02:29:09
and is from zero to one then it
02:29:11
is the root of the equation notch canada
02:29:14
one if x 2
02:29:16
satisfies this condition and is from zero
02:29:18
up to one then it is a root
02:29:21
equations for 3 scanner unit
02:29:23
we can't have both roots at once
02:29:27
were the cube roots of the equation for the segment
02:29:30
which will move because we will have
02:29:31
then two roots
02:29:32
but we need to have only one root
02:29:34
let's find out at what a x 1 will be
02:29:37
suitable then we will find out at what aek 2
02:29:40
will be suitable then we will find out at what
02:29:44
and they match
02:29:45
and then we’ll write down at what a
02:29:49
how many roots and some roots like this
02:29:53
x 1
02:29:54
it is equal and so it is the root
02:29:58
equations for a satisfying two
02:30:03
conditions, firstly, this root must
02:30:06
satisfy the water for the second time
02:30:09
must lie in the range from 0 to ones
02:30:12
substitute x 1 equals a under x
02:30:16
we substitute a and we get a squared
02:30:18
minus a squared b is equal to 0 and
02:30:22
a must be from zero to one so 0 a
02:30:27
the square is greater than or equal to 0 for any a0
02:30:31
greater than or equal to 0 for any and you know
02:30:34
So all we have left is this
02:30:37
double inequality that is, what is the conclusion
02:30:40
output at
02:30:41
and from zero to one inclusive
02:30:45
x 1 which rabbi is the root
02:30:49
equations on the interval and for others they
02:30:54
are the roots of the equation well or yes for
02:30:56
and violated either not sodium skill and lies
02:30:58
so is the root of the equation a x 2
02:31:06
we have it equal to half a + 1 2 and so
02:31:12
the root is the root of the equation at a
02:31:15
satisfying review x square minus a
02:31:21
square is greater than or equal to 0 and when is it
02:31:24
lies in the interval from 0 to a minute, well
02:31:26
so we substitute this thing for x
02:31:29
on or this view is more convenient
02:31:32
substitute what do you think, well, I think in /
02:31:37
/ it’s more convenient to substitute a friend, it’s more convenient then
02:31:40
it turns out that instead of x I substitute a +
02:31:43
1 second squared minus a squared b
02:31:48
equals 0 and a + 1 second must be from
02:31:52
zero to one so we need to solve it
02:31:58
solve by 4 can be multiplied and here by 2
02:32:02
it turns out a plus 1 squared minus 4 a
02:32:09
square is greater than fat 0 by 4 multiplying
02:32:12
because 2 squared 4 is this
02:32:13
denominator 4 will be understand therefore I
02:32:15
download 4 multiply top denominator me not
02:32:17
it was like this here by 2, multiply it turns out
02:32:19
a + 1 from 0 to 2
02:32:24
open the brackets a square plus 2 plus
02:32:29
1 minus 4x square subtract here
02:32:34
one from all three sides and double
02:32:35
inequalities a from -1 to 1
02:32:39
so it turns out minus 3 and the square is plus 2
02:32:43
plus 1 is greater than or equal to 0 and from -1 to 1
02:32:51
we need to solve this thing and solve it in
02:32:54
the system will probably have an inconvenience later
02:32:57
or or ok what kind of roots are there?
02:33:02
if according to the discriminant your roots are 4
02:33:05
+ 12 16 roots normal shorter
02:33:08
what are the roots of this?
02:33:12
inequalities so discriminant 4 + 12 16
02:33:19
minus 2 plus minus 4 divided by minus 6
02:33:23
minus 2 minus 4 times minus 6 is 1 -2 + 4
02:33:31
this is 2 to minus 6 minus one third well I
02:33:35
I don’t describe it again as a discriminatory
02:33:37
they also think you understand how to do this
02:33:40
minus plus minus we need pluses from
02:33:43
colored dot and should be
02:33:47
-1 to 1
02:33:51
find the intersection we need to find
02:33:53
we can find the intersection by intersection
02:33:56
Orally you can write it from -1 to 1 and
02:34:03
while canceling from 1 1 1 3 to one well
02:34:06
in short, let's show its intersections with
02:34:11
we apply -1 we apply minus one third
02:34:16
put one and so the first answer from
02:34:19
-1 3 d and girls second answer from -1 to 1
02:34:24
where there are 2 hatches there is the answer, that is, the conclusion
02:34:29
with and with proper from -1 3 to unity
02:34:37
x 2 which is equal to what is 1 2 a + 1 2
02:34:49
is the root of the equation at a given
02:34:51
segment for others and not for these or for
02:34:55
even violates or does not lie on the segment
02:34:56
so is the root of the equation on the interval
02:35:05
well is the root of the equation okay so
02:35:09
this means x 1 is the root of the equation at
02:35:12
these a x 2 is the root of the equation at
02:35:15
these and and when they coincide
02:35:19
x 1 coincides with and to old when and when
02:35:29
what situation so if it means x 1 is equal
02:35:32
a a x 2 is equal to half a + 1 2 to x 1
02:35:40
equals 1 equals xt room so let's solve
02:35:42
throw this equation 1 2 to the left
02:35:44
there will be 1 2 and well, minus one second and this is
02:35:48
will be 1 2 equals 1 2 equals one output
02:35:54
when a is equal to 1 x 1 coincides with k old
02:35:59
And
02:36:04
x 1 equal to and which is equal to what
02:36:08
if a is equal to 1 x 1 is equal to 1 week 2 is equal to
02:36:12
1 2 + 1 2 is also 1 and so we are ready for
02:36:19
do the last thing we do
02:36:21
number line and construct a number line
02:36:23
and apply to it everything that affects
02:36:28
the number and quality of roots are shorter by
02:36:32
number of roots
02:36:33
Well, does x 1 x 2 exist?
02:36:36
x 1 the root of the equation depends on a
02:36:40
what is from zero to one yes that is us
02:36:42
put zero one minus one third
02:36:46
and one and one, that is, we apply
02:36:50
minus one third zero one
02:37:01
make three sticks
02:37:14
Let's consider the situation when a is less than
02:37:16
-1 3 when a is exactly minus one third
02:37:20
when a is from -1 3 to zero when a is exactly
02:37:26
zero when a from zero to one
02:37:29
when a is equal to 1 when is greater than 1 so if
02:37:34
and less than -1 3 how many solutions what for
02:37:37
solution if a is less than -1 3 x 1
02:37:42
no it is not the root of the equation if
02:37:45
and less than -1 3 x 2 no he is not
02:37:47
root of the equation
02:37:48
there are no roots if exactly minus one third
02:37:55
then x 1
02:37:57
there is none x 1 is the root of only
02:38:00
zero to one and x 2 is the root of
02:38:03
at minus 1 3 is shorter that is x
02:38:07
2 is the root of the equation x 2 in general
02:38:10
was remember 1 2 a + 1 2
02:38:13
so with a equal to minus one third
02:38:16
it is equal to 1 2 multiplied by
02:38:21
minus one third + 1 2 that is, it is equal
02:38:26
minus 1 6 + 3 sixths 2 sixths is 1 3 he
02:38:33
equal to one third
02:38:34
we have only one root, which means this
02:38:36
I'm happy with it, she'll go in return
02:38:38
further if a from -1 3 to zero x 1 is
02:38:44
interval from -1 3 to zero
02:38:46
they enter, well, they enter here
02:38:50
no not included x 1 no and interval from -1
02:38:54
3 0 is included in this segment to include
02:38:56
therefore for the second there is here there is x
02:38:59
2 is just the only root of 2
02:39:01
therefore they are not satisfied with such people if a
02:39:04
exactly zero then x 1
02:39:07
but is the root of the equation zero
02:39:10
included in the interval from zero to one
02:39:12
this means x 1 is the root of the equation
02:39:16
x 1 is the root of the equation and it is equal to
02:39:19
well, given that it is equal to 0 it is equal to 0
02:39:22
and x 2 is the root of the equation and 2
02:39:26
is the root of the equation for the drive of these a
02:39:29
there's a zero here somewhere inside that means
02:39:33
the second one is also the root of the equation it
02:39:36
generally equal to usually 1 2 a + 1 2 means
02:39:40
if a is equal to zero then it is equal to 1 2 for us
02:39:44
it turned out that when a is equal to zero two
02:39:46
We are looking for different roots and for which there will be
02:39:49
one root
02:39:50
it means I don’t need it anymore if from
02:39:53
zero to one x 1 is the root of the equation a from zero
02:39:58
to one are in the interval from zero
02:40:00
to one means x 1 is the root
02:40:02
equations
02:40:03
x 1 are equal to a is by the way here 1 2 a +
02:40:09
12
02:40:10
so x 1 is the root of the equation x
02:40:12
2 is the root of the equation on the interval
02:40:14
from zero to one to
02:40:16
the segment from zero to one is located on
02:40:18
crack cancel from 1 3 from minus 3 to units
02:40:22
that is, x 2 which is equal to one second a
02:40:25
+ 1 2
02:40:27
here he is also the root and everything
02:40:29
we have two roots
02:40:30
we already had two roots
02:40:34
this is zero 1 2 2 different roots and here
02:40:36
maybe the same roots no roots maybe
02:40:39
be the same only if a equals 1
02:40:41
a little further we will look like this if
02:40:45
equals 1 x 1 is the root of the equation yes
02:40:48
because or equals 1 and or equals 1
02:40:52
Means x 1 is the root of the equation he
02:40:57
actually equal to a but given that a
02:40:59
equals 1
02:41:00
it is equal to one x 2 is the root
02:41:02
equation and 2 is the root of the equation
02:41:05
given and therefore if a is equal to 1 . 2
02:41:08
is the root of the equation it is usually
02:41:12
is equal to 1 2 a + 1 2 but if a is equal to 1 then
02:41:15
it turns out to be equal to one yes we have
02:41:17
again two roots for the third time in a row two
02:41:20
root but in the data at the moment the roots
02:41:23
we have two coinciding roots
02:41:26
coincide, that is, there are one different roots
02:41:29
thing
02:41:30
and that’s why this suits me
02:41:33
if a is more than one then ray a is more
02:41:39
one is not here means x 1 not
02:41:41
is more the root of the equation
02:41:43
you can’t get more than one here either
02:41:45
is therefore not located to the old one either
02:41:47
is the root of the equation and here it’s simple
02:41:49
there are no roots for a and there is more than one simply
02:41:52
there are no roots and we have only one root
02:41:58
purchased and
02:41:59
and we write them in response from -1 3 to 0 1 3
02:42:07
inclusive 0 no and free-standing
02:42:11
one now let's go over everything
02:42:14
solution the root is equal to the root when
02:42:17
when their radical questions are equal
02:42:20
why write roots they would write
02:42:22
radical is equal to under the knee so that
02:42:25
Maldiz was hung just for this purpose and
02:42:26
wrote roots but before radicals
02:42:29
we equate these rights and rights
02:42:32
and the radical was simplified, expanded either
02:42:33
by disk Renata or by Vieta on
02:42:35
multipliers using this formula
02:42:36
laid out means we remove the roots and
02:42:39
we say left radical is greater than or
02:42:41
equals 0 and given that the radicals are equal
02:42:43
then you know the right one is guaranteed too
02:42:45
greater than or equal to 0, no need to write that
02:42:47
should be right, that's what it should be from
02:42:50
zero to one to how to solve this
02:42:52
the equation just flip to the left
02:42:54
you take out a parenthesis, you decide, you decide
02:42:57
you get x 1 x 2 1 2 + 1 2 you get
02:43:01
two roots let's find out at what a x 1
02:43:05
will be the root of the equation for
02:43:07
segment that is x 1 should along
02:43:09
satisfy the water behind him lie on
02:43:11
segment it turned out that with such
02:43:13
and x 1 is a root on the segment a for
02:43:17
which a x 2 is a root on the segment
02:43:19
he needs to satisfy the dose and lie down
02:43:22
on the segment it turned out that x 2 is
02:43:25
roots on segments for such a
02:43:26
and for which a the roots must coincide
02:43:31
equate them and it turns out that for a
02:43:34
equals 1 they coincide and now we build
02:43:37
number line and where we show when
02:43:39
what and how many roots and what kind
02:43:42
specifically the roots, I found out that there is one root
02:43:46
acquired but only maybe with
02:43:49
there are either two roots or none
02:43:50
roots
02:43:51
we all wrote down and at which it will be
02:43:54
only one root, that's the problem
02:43:57
find all values ​​for each of
02:44:00
of which the equation has exactly one
02:44:01
root on the segment from 4 to 8
02:44:03
a fraction is equal to zero when the numerator is equal
02:44:05
zero and the denominator is not zero but still
02:44:08
radical must be greater than or equal to
02:44:10
0 but since the denominator since since
02:44:14
the root of the denominator is the radical
02:44:15
cannot be equal to zero, that is
02:44:18
the radical must be strictly greater
02:44:19
zero numerator equals zero radical
02:44:22
strictly more than me that is given
02:44:24
equation it is equivalent to the system where
02:44:28
the numerator is zero and the radical
02:44:30
strictly greater than 0 we write the product of two
02:44:35
brackets
02:44:36
bullets are equal to zero and the radicand is strictly
02:44:39
greater than zero so 10 x minus x square
02:44:44
minus and the square is strictly greater than 0 and also y
02:44:50
us x must be between four
02:44:52
until eight until let's log in too
02:44:54
let's turn on cocido, that is, x must be from
02:44:56
four to eight, well, it’s up to us to decide
02:45:02
equation product equals zero when
02:45:05
when at least one of the factors is 0
02:45:07
in the second there is, that is, simply
02:45:10
each to zero we equate x minus a
02:45:11
minus 7 equals zero or x plus and minus 2
02:45:17
equals zero and must be fulfilled
02:45:21
roughly speaking about the dose 10 x minus x square
02:45:23
minus and the square is greater than 0 and excel to us
02:45:27
needed only in the range from 4 to 8 so
02:45:29
let's express x from the equations that is
02:45:34
it turns out x 1 equals plus 7x second
02:45:39
equals 2 minus and it should
02:45:44
performed at a dose of 10 x minus x square
02:45:46
minus and the square is greater than 0 and x must be
02:45:50
from four to eight such a system
02:45:54
must be fulfilled
02:45:55
as you see if x 1 and satisfies
02:46:00
there for
02:46:01
and is included in the segment from 4 to 8 then it
02:46:04
is the root of the equation
02:46:05
and there is also a second one that will satisfy this
02:46:08
for is the root of the equation we have two
02:46:10
root but we need to have one root
02:46:12
let's find out at what a x 1 is
02:46:16
root then we will find out at what a
02:46:18
x 2 is a root then we find out when
02:46:21
what and they coincide and two roots
02:46:24
turn into one single root
02:46:25
and then we'll look at the end before answering
02:46:28
at what and how many roots and what are they?
02:46:31
roots and then we will know at what a
02:46:33
there will be exactly one root
02:46:35
so x 1 is the root of the equation here x
02:46:39
1 it is equal to a plus 7 when it appears
02:46:45
the root of the equation when at it is
02:46:52
the root of the equation for a satisfies
02:46:58
inequality is a to z and x must be from
02:47:01
four to eight, that is, it should
02:47:03
satisfy the system
02:47:05
10 x minus x square minus a square
02:47:10
greater than 0 and x must be between four and
02:47:12
eight we will now find out at what a x 1
02:47:16
is the root of the equation then the same
02:47:18
most done for which then when
02:47:20
they match and then write the answer
02:47:22
that means we have to substitute it right now
02:47:25
Substitute a plus 7 for x, that is
02:47:30
it turns out to be 10 times a plus 7 minus
02:47:36
x squared is minus a plus 7 squared
02:47:40
minus x squared greater than zero
02:47:42
bodex we substitute a plus 7
02:47:49
and decide, well, how to decide here, let’s go to
02:47:57
let's simplify a little, at least the second one is easy
02:48:00
solve there and from what to what -7 subtract
02:48:03
-7 out of three sides
02:48:05
inequality here one here minus 3 and from -3
02:48:08
to 1 a 1 how to solve we open the brackets
02:48:11
then ten a plus 70 minus square
02:48:15
sums that is minus and squared minus
02:48:17
14 a
02:48:18
and -49 minus square is greater than zero
02:48:23
so let's solve the first one separately
02:48:26
inequality because you still have a long time
02:48:27
I don’t want to write the second one to rewrite 50
02:48:29
once we call the inequality one given
02:48:32
so minus x square minus a square is
02:48:34
-2 and it’s a square, so we’re the first to solve -2
02:48:39
and the square is further than 10x minus 14 and this is
02:48:43
will be minus 4a
02:48:46
70 minus 49 plus 21 must be greater than 0
02:48:50
multiply by minus 1 and it turns out to be 2 in
02:48:56
squared plus 4 minus 21 when we multiply
02:49:01
on negative icon unfolds
02:49:03
less than 0 so discriminant b squared
02:49:07
minus 4 by 2 and by -21 that is plus 168
02:49:14
it turns out
02:49:20
so 106 from 8 184 184 to 184 is
02:49:28
184 is 4 times 46
02:49:36
so it turns out that a is equal to a first
02:49:41
second minus b minus 4 plus minus root
02:49:46
out of 4
02:49:47
46 is 2 roots of 46 divided by 2a then
02:49:51
is on 4 means a 1 is equal to what a 1
02:49:57
equals minus 4 divided by 4 is minus one
02:49:59
and two roots and 46 divided by 4 is 1 2
02:50:05
root of 46
02:50:07
and the second root is -1 minus 1 2 roots
02:50:12
from hands 6 but we were not solving an equation but
02:50:16
inequality therefore on the number line a
02:50:19
We apply from the left the one who is smaller -1
02:50:22
minus one second roots 46 and to the right is that
02:50:26
who is bigger, that is, minus 1 plus 1 2
02:50:30
root of 46 and set the intervals
02:50:34
plus and minus signs
02:50:36
plus we need those and in which
02:50:39
It will be less than 0, that is, minuses are needed
02:50:42
so now we need to find the intersection with a from
02:50:45
-3 to 1
02:50:46
let's find the intersections
02:50:59
-1 minus so we have -3 we have
02:51:06
one and who are these numbers approximately
02:51:10
what are they equal to
02:51:11
so minus 1 plus half roots 46
02:51:15
root of 46
02:51:16
this is 6 something, let it be 6.8 for example
02:51:20
half of 68 is 3.4 minus 12.4
02:51:25
this is approximately there to the right of everyone and minus 1
02:51:35
minus half of 68 minus 1 minus 3 4
02:51:42
minus 44 he turns out to the left of everyone and so
02:51:49
we have the answer from one to the other and from -3
02:51:54
to 1 where 2 hatches there the answer is
02:51:57
what is the conclusion
02:51:58
from -3 to 1 what what happens from -3 to
02:52:01
one from -3 to 1 x 1 is the root
02:52:06
equations
02:52:07
you understand, that is, he satisfies
02:52:10
friends and is in the range from 4 to 8
02:52:12
therefore, for a from -3 to 1 x 1
02:52:21
which is the same as there x 1 that was a plus
02:52:27
7x plus 7 is the root of the equation for
02:52:33
segment
02:52:37
and the satisfying dose is shorter
02:52:40
root of the equation
02:52:41
let's find out x2 when is the root
02:52:44
equations and the second is equal we had 2
02:52:46
minus and we do the same thing
02:52:49
so x 2 are two minuses and he is
02:52:55
root of the equation for a satisfying
02:53:01
system, that is, he is for
02:53:04
it is necessary that 10 x minus x be executed
02:53:07
square minus and square greater than zero to
02:53:13
and x must lie in the range from 4 to 8
02:53:16
let's find out x 2 for what a is
02:53:19
root of the equation
02:53:20
let's substitute it turns out let's on the left
02:53:26
write that is 10 multiplied by x is 10
02:53:30
by 2 minus a minus 2 minus a squared
02:53:35
and minus x square is greater than 0x from 4 to 8 then
02:53:41
there are two minuses there must be four or more
02:53:43
up to eight
02:53:47
the knot 1 5 long to decide let's do it
02:53:50
let's simplify by 1 2 for now we'll solve like this 20 minus
02:53:54
10 and minus 4 minus 4 plus 4 minus to
02:54:02
plus a square turns out to be a minus square
02:54:04
there we change all the signs to because minus
02:54:05
before the brackets there is a minus and the square is greater
02:54:08
zero here we subtract 2 from all sides
02:54:12
double inequality, that is, there will be 2
02:54:14
minus a and six we give similar
02:54:19
minus 2 square minus 10 plus four is
02:54:24
minus 6a
02:54:27
2416 must be greater than zero by -1
02:54:31
multiply, that is, it turns out a from minus 2
02:54:38
to minus 6 but the icons need to be expanded
02:54:40
because they pressed negative here
02:54:43
must be from -6 to -2 and
02:54:47
and that means we need to solve this inequality
02:54:50
let's call it number 2 and solve
02:54:53
it separately also with discriminant
02:54:54
now let's solve the second inequality by
02:54:58
discriminant
02:54:59
firstly, you can divide by -2, that is
02:55:03
will be a squared plus 3a minus 8
02:55:07
less than zero discriminant 9 + 3241 a
02:55:15
equals minus 3 plus minus root of 41
02:55:19
secondly, that is, we are on the number line
02:55:23
apply -3 minus root of 41
02:55:29
second and -3 plus root of 41 second
02:55:35
place intervals with plus and minus signs
02:55:38
plus
02:55:39
we need minus signs and we need to find them
02:55:43
we find the intersection with a from -6 to -2
02:55:47
baptism
02:55:55
so we put it on the number line
02:55:59
minus 6 and minus 2 and these two numbers
02:56:02
so they will take approximately what they are equal to
02:56:05
root and 40 1 is about 6 and a bit
02:56:08
well let it be 6.4
02:56:10
minus 3 plus 6 4 that would be 3-4 in half
02:56:15
this is one and seven about 1 whole 70's then
02:56:18
there is he more right than everyone else
02:56:27
and here minus 3 minus 6 and 4 it will be
02:56:32
minus 9 4 in half minus 4.7 that is, he
02:56:37
not to the left of everyone -6 to the left of everyone then goes
02:56:41
here it is and then it goes minus 2
02:56:49
filled in and so one of the answers from -6 to
02:56:54
-2 and the other from fraction to fraction where 2
02:57:01
shading there answer 2
02:57:03
well, the short answer is the drive of these and where
02:57:09
now the intersection x 2 is the root
02:57:11
equations therefore for these
02:57:17
and that is, and with proper from -3 minus
02:57:21
root of 41 second to minus 2 here at
02:57:28
such a x 2 is the root of the equation
02:57:31
is the root of the equation
02:57:40
so let's now learn about x 1 x 2 at
02:57:44
which a coincide let's find out x 1
02:57:51
matches old iq
02:57:57
if something like this happens x 1 it was y
02:58:01
us a plus 7 x 2 is 2 minus a if a
02:58:06
plus 7 equals 2 minus
02:58:10
an error to the left turns out to be 2 and a seven
02:58:13
to the right it turns out minus 5 equals minus
02:58:16
two and a half that is, if a is equal
02:58:18
output when a is equal to minus 2 and a half x
02:58:25
1 is equal
02:58:26
and to the old even what they are equal to we can
02:58:29
understand minus 2 and a half substitute
02:58:31
or they would have served it here at up to minus 2 s
02:58:34
half plus 7 equals four s
02:58:35
half that is
02:58:38
there are 2 roots but they coincide and everything is like
02:58:40
there are 1 roots 1 pieces four s
02:58:42
half kick and match so we all
02:58:49
are now ready to analyze at what a
02:58:51
how many roots will there be
02:58:52
and what is behind the root we do the final
02:58:54
number line a and plot all a
02:59:02
influencing the appearance of x 1 x 2 and
02:59:07
coincidences there x first 2 that is us
02:59:09
apply
02:59:10
and these are from -3 to 1
02:59:15
these and minus 2 and a half
02:59:21
so we apply minus 3 and one we apply minus
02:59:25
3 and let one be here -3 for example here
02:59:29
there will be one further, you need to apply another minus
02:59:34
2 and this is the number that is approximately
02:59:38
minus 47
02:59:39
that is, it is to the left more to the left it turns out to be more to the left
02:59:42
always Libya we all have this one / -3
02:59:49
minus the root of 41 second
02:59:54
minus 2 is further to the right than -3 obviously
02:59:58
so minus 2 and a half is still needed
03:00:00
apply minus 2 and a half will be exactly
03:00:02
between minus 3 minus 2 minus 2 s
03:00:04
half of them are now small sticks
03:00:07
we do
03:00:20
so let's look at a first
03:00:25
which is less than this fraction is a minus
03:00:27
3 minus the root of 41 second let's look at
03:00:31
which are smaller than which then
03:00:32
Let's look at a equal to this fraction
03:00:35
what kind of roots will there be and how much will it feed?
03:00:37
then let's look at and which are from fractions to
03:00:43
-3 then look at a is equal to -3 then
03:00:47
Let's look at a from -3 to minus 2 s
03:00:49
half then look at exactly minus
03:00:52
2 and a half
03:00:53
then let's look at a from minus two c
03:00:55
half to -2 then look at a
03:00:59
equals minus 2
03:01:03
then let's look at a from minus 2 to
03:01:06
units
03:01:08
then look at equal to 1 yanao more
03:01:10
units so if a is less than / if a
03:01:15
less than /dx 1 is the root
03:01:18
there is no equation x 1 is the root
03:01:21
equations for such and that is, a fraction
03:01:24
fraction is not included it is minus 4 something
03:01:26
is not included in this segment x 1 is not
03:01:28
root x 2 is the root of the equation
03:01:31
no fractions are not included because these
03:01:36
the parenthesis does not include the fraction and
03:01:37
which does not exist, that is, to the left than / no
03:01:40
no roots x 1 not 2
03:01:44
if a is equal to / again then x 1 being
03:01:49
is the root of the equation no x 1 not
03:01:52
included
03:01:53
well, more precisely, a fraction and does not include from -3 to
03:01:55
1 is not included in this risk therefore x 1 no
03:01:58
and x 2 no there is a parenthesis yes therefore
03:02:04
there are no roots if we take some
03:02:10
number between fractions minus 3y minus 4
03:02:13
for example -4 is included in the segment from -3
03:02:18
This means that x 1 is not the root of x 2
03:02:21
root that is, if we take
03:02:23
interval from fraction to -3
03:02:27
then this interval is included in this
03:02:31
interval x 2 means will be here is
03:02:33
root opinion x 2 will be the root here
03:02:37
equation it will be equal to 2 minus
03:02:39
x 2 is equal to 2 minus, that is, when
03:02:42
these and we have only one solution
03:02:46
circle this about the one we were looking for good
03:02:50
so if a is equal to minus 3 x 1 is
03:02:54
the root of the equation until we see a quadratic
03:02:56
the bracket x 1 is the root of the equation
03:02:58
if a is equal to minus 3t x 1 is
03:03:00
the root of the equation and it is equal to what it is
03:03:04
equal to a plus 7, like double a plus 7
03:03:07
but if a is equal to minus 3 then it is equal to
03:03:11
it turns out it is equal to minus 3 plus 7 then
03:03:15
is it equal to 4 4 x 2 what is x 2 equal to
03:03:22
so if a is equal to minus three minus three
03:03:24
come here started 2 is the root
03:03:27
equation and 2 is equal to something else two
03:03:30
minus but something else and not 2 minutes myself and
03:03:33
we know that it equals -3 to
03:03:36
equals 5x 1 equals four x 2 5
03:03:40
they are different two roots but something happened
03:03:43
root to
03:03:44
we don’t need two roots, that is, we don’t need -3
03:03:47
suitable if we take a from -3 to
03:03:50
minus two and a half from -3 to minus
03:03:54
two and a half interval is included in
03:03:55
this segment yes means x 1 will be
03:03:58
be the root of the equation a plus 7x so
03:04:04
and from -3 to minus two and a half are included
03:04:07
in this period, yes, that means 2
03:04:10
will be the root of the equation and it
03:04:12
will be equal to 2 minuses and they will be different
03:04:15
we will have two roots, I don’t need two
03:04:19
roots I need there was one root
03:04:21
if a is equal to minus two and a half then
03:04:24
minus 2 and a half and are in this
03:04:27
segment yes means x 1 is a root
03:04:29
equations x 1
03:04:32
it will be a plus 7 but since we know a
03:04:37
it turns out four and a half, well if -2
03:04:42
spray on you will sleep well x 2 so
03:04:46
minus 2 and a half and in well is in
03:04:48
in this interval yes means and which
03:04:50
is the root of the equation and it is equal to 2
03:04:53
minuses but considering that we know what
03:04:55
the same and the same will happen with half then
03:04:57
before we had two roots two
03:04:58
there are two roots again, but these are two
03:05:01
coinciding roots therefore a is exactly minus
03:05:09
2 and a half in return will go with him
03:05:12
there will be two matching roots further if
03:05:16
and from minus two and a half to -2 from
03:05:21
minus two and a half to -2 are included in
03:05:23
segment in this yes therefore x 1 is
03:05:26
the root of the equation and it is equal to a plus 7a x
03:05:31
2 equals 2 minus
03:05:32
so their sides are from minus two and a half
03:05:36
up to -2 are included in this segment up to therefore x
03:05:38
2 will be the root of the equation will
03:05:41
2 minus 7 we will have two different roots
03:05:44
those that don't match already they only match
03:05:46
about two and a half further if a is equal to minus 2 minus 3
03:05:50
minus 2 x 1 is the root of the equation -2
03:05:53
are included here yes therefore x 1 is
03:05:56
root of the equation x 1
03:05:58
it is equal to x + 7, well, considering that a
03:06:02
is equal to minus 2 it turns out it is equal to 5 so
03:06:06
and minus 2 come in here and see the square
03:06:10
the bracket means the second one is also there and he
03:06:14
equals 2 minus and there were 2 minuses here
03:06:20
2 and minus and here it was like that here too
03:06:22
two minuses there 2 minus the author's root
03:06:27
two minuses so two minuses and considering
03:06:30
what and this is minus two makes four
03:06:33
remember we had a situation x 1 4 2 5 a
03:06:36
the forest is the opposite x 1 5 2 4 but we have it again
03:06:38
two roots that are not the same, they coincide
03:06:41
only at -2 alloy
03:06:42
so we don’t circle this, we need one
03:06:45
take the root
03:06:46
interval from minus 2 to 1 interval from
03:06:49
minus 2 to 1 per turn well lies here on
03:06:52
this segment yes therefore x 1 here
03:06:54
exists and it is equal to a plus 7 from minus
03:07:00
2 to 1 are
03:07:03
here from minus 2 to 1 are included in
03:07:06
segment in the interval from fraction to -2 no
03:07:08
that's why he's not here and here we are
03:07:11
found and at which there will be only one
03:07:13
solution ks 1 if a is equal to 11 when a is equal
03:07:19
1 x 1 is the root of the equation
03:07:21
yes, and because it’s square
03:07:23
the bracket when a is equal to 1 x 1 is a root
03:07:27
equation it is equal to a plus 7 but given
03:07:30
that a is equal to 1 it turns out it is equal to 8 one
03:07:32
plus seven eight a x 2 no x 2 at all
03:07:36
more to the right than minus 2 x 2
03:07:38
but it is not the root of the equation
03:07:39
therefore a is equal to 1 and we are further suited to a
03:07:43
more than one and more than one is not included
03:07:46
during this period
03:07:47
therefore x 2 x 1 will not be here and which
03:07:51
there are simply no roots here either and what comes out
03:07:55
it turns out that we circled
03:07:57
and for which there will be exactly one solution
03:07:59
on the segment, that is, the answer is from -3
03:08:07
minus the root from the hands of one second to -3
03:08:13
then free-standing minus 2 s
03:08:15
half and from minus 2 to one
03:08:22
square bracket everything so again than
03:08:27
we did the fraction equal to zero when
03:08:29
when the numerator is zero and the denominator
03:08:30
is not equal to zero and the radical must also
03:08:32
be greater than or equal to 0 but since it is in
03:08:34
the denominator is strictly greater than zero
03:08:35
radical, that is, initially and
03:08:38
equation equivalent to the numerator system
03:08:41
is equal to zero and the radical is greater than zero but
03:08:43
x must also fall within the range from 4 to
03:08:45
8 the equation can be easily solved we found
03:08:47
x 1 x 2 we also have, roughly speaking, dc
03:08:50
x 4 to 8 and we think so and at what
03:08:53
and x 1 will be the root of the equation
03:08:54
very easy when he satisfies there
03:08:57
for and when he is in the segment 4 to 8 we
03:08:59
we find these and here they are, the drive of such and
03:09:02
x 1 root of the equation a x 2 for what a
03:09:05
is the root of the equation very easily
03:09:08
when she hits friends and but also lies
03:09:09
in the segment 4 to 8 it turns out that at
03:09:13
these
03:09:14
a and k is the second root of the equation okay a
03:09:16
for which a x 1 coincides with x2 priors
03:09:19
to minus 2 and a half grade is now at
03:09:21
number line and plot everything
03:09:24
values ​​and on which it depends
03:09:26
number of roots and types of roots
03:09:28
what are the roots equal to, so we look at
03:09:31
like this
03:09:32
and x 1 there is no x 1 there is not and which
03:09:35
no no roots either
03:09:36
but with this there are roots
03:09:39
there are no roots, but with this a x 1 x 1 there are no
03:09:44
x 2 already exists, so there’s only one here
03:09:47
the root means these and they suit me well
03:09:50
this is how we scan to the end and find
03:09:52
for which a we will have either x 1 or x
03:09:55
2 thousand will be exactly one root or something
03:09:57
two roots but they coincide at
03:09:59
this is such a task
03:10:03
find all values ​​for each of
03:10:05
of which the equation has exactly one
03:10:06
root on a segment from 0 given
03:10:08
Well, obviously x-man can’t be thrown to the left
03:10:12
will be x square minus x taken out for
03:10:14
bracket there will be bracket x minus 1 and here
03:10:16
I x1 remove this bracket
03:10:18
and then there will be a product of two
03:10:21
factors equal to zero shorter than x squared
03:10:24
move x to the left with a minus and further
03:10:28
rewrite
03:10:35
now we put x outside the bracket further
03:10:40
rewrite
03:10:46
now we remove the parenthesis as general
03:10:48
factor
03:10:54
x plus root of 3 x minus a must be
03:10:58
is equal to zero so when the product is equal
03:11:01
zero when at least one of the factors
03:11:02
is equal to zero and the second one exists, that is
03:11:05
we say that x minus 1 is equal to zero or
03:11:11
x plus the root is equal to zero and
03:11:19
radical and must be greater or
03:11:21
equals 0 and x must be from 1
03:11:25
the unit series x must be from zero to
03:11:30
units so we get such a system, well
03:11:35
I already solved the first equation
03:11:37
the second one needs to be solved there the second one needs to be solved
03:11:39
decide the second you have to sit and decide like this
03:11:43
so I think maybe the second one is separate
03:11:45
write it out and now resolve it with the old one
03:11:48
figure it out and then return to the system
03:11:49
let's deal with
03:11:54
in the second equation we return to the system
03:11:57
so let's call it number 1
03:12:02
equation and let's figure it out x
03:12:06
plus root equals zero
03:12:11
let's leave the root in one country 3x
03:12:14
minus y equals minus x equals x
03:12:17
to the right and on the other side the root is equal to
03:12:20
minus x what are you, how to decide
03:12:22
rational equations we are talking about
03:12:26
that the root cannot equal
03:12:27
negative number yes that is we
03:12:28
we say that the right side is larger or
03:12:30
equals 0 and then square both sides
03:12:33
build like this but if minus x is greater or
03:12:41
equal to 0 means x is less than or equal to 0 and x
03:12:43
there can only be 0 to ones that is
03:12:44
only 0 suits us so x is equal to 0
03:12:49
in general so how how how the nights are here
03:12:53
transition is an equivalent transition such that
03:12:56
the right side must be greater or
03:12:58
equals 0 and then can be squared
03:13:00
both parts
03:13:01
if the right side is 1 deuce then
03:13:04
the radical must be a quadruple
03:13:05
understand that is, if the right side is not
03:13:07
negative then 3x minus a must
03:13:09
be turns out to be equal to the right side in
03:13:13
square minus x square like this here
03:13:16
equivalent transition
03:13:19
but let's notice, or let's let's
03:13:24
let's continue
03:13:25
minus x is greater than the mountain but 0 it is minus 1
03:13:28
multiply multiply by minus 1 and it turns out
03:13:33
x is less than or equal to 0x less time
03:13:37
than zero square and these
03:13:41
we rewrite this if x is less or
03:13:44
is equal to than 0 but in the segment it is from zero to
03:13:46
units
03:13:47
then the output is just x equals 0 to us
03:13:52
fits understand we say what it is
03:13:57
equation well this is the equation
03:14:02
this equation has a root at
03:14:09
segment from zero to one
03:14:21
root on the interval from zero to one
03:14:29
only if x is equal to zero you know because
03:14:36
that x must be less than or equal to 0 but
03:14:39
we only have a segment from zero to one
03:14:40
0 hits
03:14:41
x is either negative or zero
03:14:44
negative we don't need xs segment
03:14:46
Odynets therefore only a zero can be x
03:14:49
equals 0 is removed, that is, at this
03:14:53
equation into this equation means you need
03:14:56
Substitute a zero under x and we will understand at
03:14:58
what will happen let's write
03:15:01
let's find at what a x is equal to zero at
03:15:13
what happens and this happens, that is, it is necessary
03:15:15
substitute into the original equation under x
03:15:18
substitute the zero plus the root of 3
03:15:22
multiply by zero
03:15:24
minus is equal to zero, that is
03:15:29
radical equals zero minus a equals
03:15:32
zero must be equal to zero
03:15:34
output at
03:15:38
a is equal to 0 when a is equal to 0 x is equal to well
03:15:44
such a conclusion
03:15:47
let's go back to our system
03:15:49
back to the system
03:15:59
we had a system and so x minus 1
03:16:04
equals zero let's finally decide
03:16:06
the equation x is equal to 1 that is x 1 is equal to
03:16:09
one so what is x 2 0 equal to and here is x 2
03:16:14
is equal to zero only it is equal to zero at
03:16:16
equals zero, this should still be done
03:16:20
condition 3x minus a greater than i equals 0 for
03:16:23
each of them is clearly 2 executed
03:16:24
so and k must be from zero to one
03:16:26
Well, it’s clear that they are both from one
03:16:29
it turns out x is equal to 0 from x 2 x 2 will be y
03:16:33
let's call us the old one like this
03:16:39
was x 1 let's return to the system means x 1
03:16:44
equal to zero on to so that only for him y
03:16:46
yes for made from yes so here you go x 1
03:16:51
it is equal to unity for what a and for a
03:16:57
satisfying the following conditions
03:16:59
firstly must be performed in
03:17:01
secondly, x must be in the interval from 0
03:17:03
up to 1 glass
03:17:04
from zero to one therefore for questioning
03:17:06
so that ode for fulfills so that 3x minus a
03:17:08
was greater than and equal to 0 if x is 1
03:17:12
it turns out you need to multiply 3 by x by 1
03:17:14
minus a is greater than equal to 0 it turns out to be a
03:17:17
less than or equal to 3 output when a is less
03:17:25
or equal to 3 x 1 equal to one then
03:17:30
is x 2 is equal to zero at exactly zero and
03:17:32
no other way
03:17:33
and x 1 is equal to one if less than or equal to
03:17:35
than three someone will say and you finally
03:17:38
checked that x 2
03:17:40
hit even let's check x equals 0
03:17:44
equals 0 put a zero and a zero here
03:17:47
will be greater than or equal to 0 will be equal to 0
03:17:49
you understand that he is in the segment
03:17:52
from 0 to one but no one needs it
03:17:54
check that is essentially
03:17:58
we found out at what a x 1 is
03:18:02
root and for what conditions is a x 2 a root?
03:18:05
Let's write the equations so I didn't finish it
03:18:07
a little bit when a is equal to 0 and 2 is equal to 0
03:18:09
is the root of the equation at a given
03:18:12
segment and when a is less than or equal to 3 x 1
03:18:22
is the root of the equation at a given
03:18:29
segment can they coincide zero and
03:18:34
unit
03:18:35
no they don't match now let's
03:18:38
Let's see at what and how much we have
03:18:41
roots and what are the roots of the number line a
03:18:49
we are interested in a exactly zero and a less
03:18:52
or equal to 3 that is, we apply
03:18:53
just zero to three and consider
03:18:59
situation a less than zero a exactly zero a from
03:19:05
0 to 3
03:19:06
ara inside and more 3 2 sticks
03:19:13
we'll build it like this
03:19:18
so if a is less than zero
03:19:23
x 1 is the root of the equation x 1
03:19:26
is a root if a is less than
03:19:28
3 a less than zero enters the beam a less
03:19:31
or equal to 3 that is x 1
03:19:34
here is equal to one for such a x 1 is equal to
03:19:37
unit
03:19:38
and x 2 x 2 is a root only for a
03:19:41
equals 0 so there is only x 1 root
03:19:45
if a is equal to 0 then the zero is located
03:19:49
less than or equal to three therefore x 1
03:19:51
is the root of the equation to units a x
03:19:54
2 is also a root of the equation because
03:19:56
that it is the root of the equation at
03:19:58
is equal to 0, that is, 2 is equal to zero and we have here
03:20:02
two roots before there was one root
03:20:06
then two roots so if from zero to three
03:20:09
0 to 3 is included in this ray therefore x 1
03:20:13
here is the root of the equation it is equal to
03:20:15
alone and with the old ones never again
03:20:17
is he then he was here like that
03:20:20
if a is equal to 3 x 1 is the root
03:20:22
equation is equal to one if a is greater than
03:20:25
3 then we simply have no roots at all and
03:20:28
so I had to find and at which
03:20:31
we have exactly one root
03:20:33
exactly one root exactly one root
03:20:36
when a is less than zero when from 0 to 3
03:20:40
inclusive therefore the answer is from
03:20:47
minus infinity to 0 and from 0 to 3
03:20:52
let's go over the entire solution inclusively
03:20:55
find the value of a for each of which
03:20:58
the equation has exactly one root
03:21:00
segment, but the transformation x is also obvious
03:21:02
left then take out x then take out
03:21:04
parenthesis then when the product is equal
03:21:07
zero when each bracket is equal to 0 plus
03:21:09
1 curtain plus x from 0 to ones equation with root
03:21:13
we're sorting it out here, we're starting it
03:21:15
it’s up to us to decide, squaring it
03:21:17
not useful, yes, that is, we started
03:21:18
decide understood that x must be less
03:21:20
zero but if we have a segment from zero to
03:21:23
units then x is less than or equal to 0
03:21:26
only 0
03:21:29
why did we understand that x is zero in
03:21:33
in the second equation x only the role of zero
03:21:35
maybe it's equal and we all wanted it
03:21:38
find out at what point a x is equal to zero and
03:21:40
put a zero under x here and realized that
03:21:43
also a zero
03:21:44
and only if they are both zeros then we have
03:21:48
there will be a solution on a given interval here
03:21:51
if they are both zeroes the first equation is we
03:21:54
solved, then the first equation x is equal to 1
03:21:57
the second equation x is equal to zero at equal
03:22:00
0 and that's clear x 2
03:22:02
when a equals 0 is the root of the equation
03:22:05
aix are the first for which a is a root
03:22:07
equations for blowing hot doses and then
03:22:11
that it is in the interval from zero to one and
03:22:12
so and so it’s clear he’s just a unit
03:22:15
it turns out that 1 x 1 satisfies for a
03:22:19
less than or equal to 3 so with a less than or
03:22:21
equals 3 x 1 is the root of the equation
03:22:23
aprio exactly 0 and 2 is the root
03:22:26
we carried the equations onto the number line
03:22:28
everything depends on what they have
03:22:31
we looked at the roots of the equation when
03:22:33
and less than zero we only have x 1 at
03:22:35
and equal to zero we have two roots for us this is not
03:22:37
it is necessary at a from zero to three
03:22:39
only x 1 at a exactly 3 x 1 at a
03:22:42
there are no more than 3 roots at all
03:22:44
we circled circled and at which it will be
03:22:47
exactly one root and I am the answer
03:22:52
find all values ​​of a for each of
03:22:55
whose equation has a unique
03:22:56
root on the interval from -1 to 1 well on
03:22:59
square equals square let's write it down
03:23:02
difference of squares that is, we will bring
03:23:04
the right side to the left with a minus turns out
03:23:08
x square plus square root minus
03:23:16
we also move the right side with a minus
03:23:22
to the left plus the difference of squares is zero
03:23:28
further
03:23:29
difference of squares formula
03:23:32
when the abbreviated multiplication formula
03:23:35
appear in some more complex
03:23:37
tasks, not everyone sees them, so I’m on
03:23:39
I'll remind you of this one more time just in case
03:23:41
shape a square minus b square
03:23:45
turns into a minus b to plus b
03:23:48
it turns out we have one bracket this is x
03:23:52
square plus root minus that's all
03:23:58
is minus 2x minus 1 minus root 2
03:24:03
the bracket is inside the bracket plus
03:24:06
the other inside with a bracket, that is, x
03:24:08
square plus root and minus x + 2x +
03:24:14
1 + root and minus x equals zero so
03:24:20
when the product is zero when although
03:24:22
if one of the factors is equal to zero and
03:24:23
the second exists so we have roots here
03:24:27
mutually destroyed
03:24:29
yes it turns out that we have either 1
03:24:34
bracket equals zero or 2 equals zero + dc
03:24:37
that is, the radical is greater than or equal to 0 and
03:24:40
plus x excellent given that is, we have
03:24:43
it turns out either x squared minus 2 x
03:24:46
minus 1 equals zero
03:24:50
or x square plus square root plus square root
03:24:53
is this plus two roots or let's do this plus
03:24:56
2x+1
03:24:58
plus two roots and minus x equals 0 plus
03:25:05
we also need to have more radicals
03:25:08
or equal to 0 and x must be in the interval from
03:25:13
-1 to 1
03:25:16
this is the system let's solve both
03:25:21
equations
03:25:22
let's find the roots and then see at what
03:25:27
and the root
03:25:28
is the root of the equation on the interval then
03:25:30
there is when he satisfies this for and
03:25:31
is on segments for which a x 1
03:25:35
at what my 2 maybe there will be x
03:25:37
3 at what a will it be the root of the equation
03:25:39
there in front of everyone, let's see what roots they have
03:25:42
we get where the first one is shorter
03:25:45
the discriminant equation is easy
03:25:47
decided yes no no I won’t be here
03:25:49
describe so as not to complicate the recording
03:25:54
solution, well, the discriminant is 4 + 48 then
03:25:58
there's eight that's four by 2 x 1 2 that's
03:26:05
minus b that is two plus minus 2 roots
03:26:09
of 2 divide by two shorter by
03:26:12
I can find the discriminant for everyone's roots
03:26:14
I hope so, that is, x 1 will be equal to 1 there
03:26:18
plus the root of 2 x 2 is equal to 1 minus
03:26:21
root of 2 and here in the second equation
03:26:30
By the way, you can notice the square of the sum
03:26:31
see x square plus 2x + 1 is x plus
03:26:34
1 squared plus 2 times the root
03:26:39
of x minus x is equal to zero and minus x is greater
03:26:45
or equal to 0 x from 0 from -1 to 1
03:26:49
further see 1 minus root of 2
03:26:53
not included included but one plus root
03:26:57
of 2 are not included
03:26:59
segment from -1 to 1 so it disappears
03:27:01
it disappears
03:27:03
all that remains is x 2 x 2 equals 1 minus
03:27:08
root of 2 it is included for now x 1 has disappeared
03:27:10
because it's not included here let's
03:27:13
we write down that we notice that x 1 is not
03:27:21
belongs to the segment
03:27:24
therefore disappears and belongs to the segment
03:27:30
-1 to 1
03:27:34
so I dropped it, but here’s the equation
03:27:37
She's how you decide to growl unusual up
03:27:40
the square of the sum plus two roots equals zero
03:27:44
notice that this expression is
03:27:45
non-negative, that is, greater than or equal to
03:27:47
0 and this is also greater than or equal to 0 tell me
03:27:50
to me when the sum of two non-negative
03:27:51
is equal to zero only when each of them
03:27:55
equal to zero
03:27:56
that is, each of the terms must be
03:27:58
equals zero, let's do this here too
03:28:02
note note that the equation x plus 1 in
03:28:15
square plus two roots has a solution
03:28:21
has a unique solution
03:28:30
only if only if each of
03:28:37
terms is equal to zero
03:28:50
each of them that's why it was x
03:28:55
1 x 2 x 1 not included it is not included
03:28:57
segment is the equation it has
03:29:00
a solution is obtained only if so
03:29:05
only if x plus 1 equals zero and 2
03:29:12
the root of a minus x is equal to zero, understand that
03:29:16
is when each term is equal to zero
03:29:19
in this case it must be fulfilled at dc and at
03:29:23
in this case x must be from 0 -1 to 1
03:29:26
person 0 I want to say this to everyone
03:29:28
such a system turns out like this x 2 expert
03:29:32
let's solve this little system
03:29:34
it turns out that x 2 is equal to 1 minus the root
03:29:38
from 2 we rewrite well here
03:29:42
he can give one to the right
03:29:44
will take x 3 x 3 equals minus one so
03:29:47
if x 3 is equal to minus one let's go here
03:29:51
let's substitute but we solve this system
03:29:53
in short and under x minus 1 we represent that
03:29:57
there is 2 times root x minus
03:30:00
minus 1 plus 1 equals zero for what a
03:30:03
this equation will be equal to zero well when
03:30:06
which and the left-hand side will be equal to zero at
03:30:09
-1 understand that is, if under x
03:30:13
substitute minus 12 will equal minus 1
03:30:19
yes, you understand, and minus x should
03:30:24
be greater than or equal to 0 and at the same time x
03:30:26
must be between -1 and 1
03:30:29
this is what should happen here
03:30:33
there were originally 3 roots it seems
03:30:35
equations x 1 x 2 x 3 x 1 everything has already disappeared
03:30:38
there are two roots left for the equation x 2 x 3
03:30:43
let's find out at what time
03:30:46
x 2 is the root of the equation x 2 is equal to
03:30:51
1 minus root of 2
03:30:54
for a satisfying the following
03:30:58
the requirement must first be fulfilled
03:31:02
even with this Mexico secondly he
03:31:07
must fall within the range from -1 to 1 but
03:31:09
well it goes like this so why do I need this
03:31:11
write everything again
03:31:13
and minus x is greater, that is, it will simply succeed
03:31:15
must be carried out with him and then he
03:31:17
is appropriate and understand so
03:31:20
minus under x I substitute one minus root
03:31:22
of 2 minus 1 plus root of 2
03:31:25
it turns out that big ones are equal to one
03:31:28
minus root of 2 output when a is greater than or equal to one
03:31:34
minus the root of 2 x 2 is the root
03:31:37
equations for others and is not
03:31:43
root of the equation on a given interval
03:31:49
good and hour x 3 x 3
03:31:53
which is equal to -1 it is generally only for a
03:31:59
is equal to minus 1, but only when a is equal to
03:32:02
minus 1 is the root of the equation
03:32:05
Is it fulfilled by dc, of course yes then
03:32:09
there is firstly here we have a minus x equals
03:32:11
zero that fits the big ones equals 0 in
03:32:13
for the second we can substitute -1 for yes and
03:32:16
Substitute -1 under x and it will also be equal
03:32:19
zero, that is, o d is satisfied for these
03:32:21
conditions and -1 is naturally included in
03:32:24
segment from what is applied to the given one, that is, x
03:32:25
3 is equal to -1 at
03:32:27
and equals minus 1 understand x 2 is
03:32:32
the root of the equation drives these a a x 3
03:32:36
is the root of the equation drive this a
03:32:38
that is, with a equal to minus 1, so let's
03:32:43
we write therefore for a equal to minus
03:32:46
1 x 3 is the root of the equation now
03:32:52
let's see at what and how much
03:32:54
roots what kind of roots are they
03:33:02
so upset straight
03:33:11
straight line and on it we put the values ​​that
03:33:15
affect the number of roots and the appearance
03:33:18
the roots are shorter and we apply one minus
03:33:21
root of 2 and minus one is a from
03:33:23
which depends there x 1 x 2 are
03:33:25
roots or not x 3 so that means we
03:33:28
apply -1 and 1 minus the root of evil is
03:33:31
to the right, that is, we apply -1 and 1 minus
03:33:36
the root of 2 MPa is made a little to the right
03:33:40
small dashes
03:33:48
we will consider the situation when a
03:33:52
less than -1 when a is exactly -1 when a is from -1
03:33:58
to 1 minus root of 2 when a is exactly 1
03:34:02
minus root of 2
03:34:03
and when a is more than one minus the root
03:34:05
from 2 so if a is less than -1
03:34:10
x 2 is the root of the equation or not x
03:34:14
2 is a root only if a is greater
03:34:16
or equal to one minus the root of 2 then
03:34:18
there is x 2 there is no trace of it but x 3
03:34:21
is the root of the equation no he
03:34:23
is the root of the equation only for a
03:34:24
equal to minus 1, that is, there is simply no
03:34:27
roots
03:34:31
if a is equal to minus 1 then x 3 is
03:34:36
the root of the equation and it is equal to -1 a x 2
03:34:40
hasn't started yet x 2 is the root
03:34:42
equations here so from means a
03:34:46
equals minus 1 is part of the answer when
03:34:48
and equal to minus 1 turned out to be the only one
03:34:50
root minus 1 xor x equals minus one
03:34:52
well if a from -1 to 1 minus the root of
03:34:57
2 then it turns out x 2 there no he is not
03:35:02
the root of the equation x 2 is the root
03:35:04
early equation drive and quiet and which
03:35:07
no, x 3 is the root
03:35:09
equations for a equal to minus 1, that is
03:35:11
there are no roots here just if a is exactly 1
03:35:18
minus root of 2 x 2
03:35:20
exists and it is equal to 1 minus the root of
03:35:22
2 x 2 is equal to 1 minus the root of 2 at
03:35:26
there are some like that and we have one now
03:35:30
minus root of 2
03:35:31
and that means 2 1 minus q2 and x 3 exists
03:35:35
only well is the root smoother only
03:35:37
if a is equal to minus 1 then there is such a
03:35:40
I'm happy if there's more than one
03:35:43
minus the root of 2 x 2 is equal to 1 minus
03:35:45
root of 2
03:35:46
and x 3 no, by the way, is only a root
03:35:52
when a is equal to minus 1, that is, they are not like that
03:35:54
we're happy too, write down the answer
03:36:00
Suitable for us, but free-standing is a minus
03:36:04
one and the ray from 1 minus the root of 2 to
03:36:08
plus infinity let's briefly go over
03:36:11
to the whole decision we have a situation from the beginning
03:36:15
square equals square
03:36:17
throw the difference from the right square to the left
03:36:20
squares we get the difference of squares
03:36:21
write it as a minus b by a plus b
03:36:23
simplify we get two equations 1 easy
03:36:26
discriminant for two roots found one of
03:36:28
they immediately disappear because they are not included
03:36:30
in this segment, that is, x 1 is missing
03:36:32
left x 2 and this equation is like this
03:36:36
unusual to analytical we need to solve
03:36:39
notice the square of the sum plus two roots
03:36:41
me negative plus not negative
03:36:44
is equal to zero only if each of
03:36:45
terms is equal to zero, so he said that
03:36:47
every term is equal to zero then x
03:36:50
is equal to -1 when a is equal to minus one comes out
03:36:54
that initially the equation had to do with
03:36:56
three roots and we need to find and at which it will be
03:36:59
only one of the roots will remain
03:37:01
segment from -1 to 1 x 1 dropped immediately from
03:37:05
the remaining two roots of 2 are
03:37:08
root of the given a
03:37:09
and x 3 is a root only for a
03:37:13
equal to minus 1 we are on the number line
03:37:15
caused everything and affecting that
03:37:18
is xyg also a root of the equation?
03:37:20
but for such and not x 2 x 3 are not
03:37:24
the root of the equation for a is equal to minus 1 x 3
03:37:28
is the root of the equation when equal to -1
03:37:31
aek parties is not therefore total
03:37:35
one guy means it suits us if
03:37:37
and from -1 to 1 root of 2
03:37:40
neither the first nor the second is shorter
03:37:42
we have also found a situation where they
03:37:44
only x 2 is the root of the equation
03:37:46
given and all this was written down in response
03:37:48
end
03:37:51
find all values ​​of a for each of
03:37:53
of which the equation has exactly one
03:37:55
root on the interval from 0 to 1 let's say that
03:37:59
move from the right to the left with a minus then
03:38:01
we’ll make the general ones and then decide when
03:38:06
the product is equal to zero when at least
03:38:07
one link that I am equal to zero plus even
03:38:09
for the entire in x from zero to one
03:38:11
classic that is root x + 2 multiplied
03:38:17
by ln x minus y equals x minus 1 times
03:38:27
on ln x minus and so it means on the right
03:38:34
move parts to the left equals zero
03:38:36
write now let's take it out
03:38:38
ln for purchase remains in the second bracket
03:38:45
root minus x minus 1 thousand minus x plus
03:38:51
1 equals zero
03:38:53
so it must be said that each of
03:38:58
multipliers equal to zero plus at the dose site
03:39:00
that is, we say that ln x minus a about
03:39:05
zero
03:39:06
root x plus 2 minus x + 1 equals zero
03:39:14
plus the radical must be greater or
03:39:17
equals 0 x plus 2 and must be greater
03:39:20
or equal to 0
03:39:21
rhythmic forgery must be greater than 0
03:39:23
strictly x must be between zero and one
03:39:28
We’ll also write it into the system, it was possible not to
03:39:31
I'll write it down for us, so now let's do it
03:39:35
let's solve two equations, solve them outside the system
03:39:42
so as not to rewrite everything else
03:39:44
we have equation 1 there is comparison 2
03:39:47
let's solve them one equation 1 l n
03:39:50
this is when the algorithm is at its core
03:39:52
there is e to the 0th power equal to x minus and then
03:39:56
there is one equal to x minus and that is x
03:40:00
is equal to a + 1 this will be x 1
03:40:04
so second second second
03:40:10
by the way, if x minus are a is equal to
03:40:13
one then x minus a is greater than 0 and
03:40:15
automatically executed i.e. for x
03:40:17
1 x minus and more than zero is not possible
03:40:19
demand, well, you can demand an extra one
03:40:21
since the second means let's use the equation
03:40:25
leave the root on one side and the rest
03:40:26
let's estimate in the other direction x plus 2 equals
03:40:31
throw excel and one
03:40:33
x minus 1 and so the root is not clear
03:40:36
what are we talking about this we are talking about
03:40:39
that the right side cannot be
03:40:41
a negative root cannot equal
03:40:43
negative, that is, we say that x
03:40:46
minus 1 or zero or more more
03:40:48
or equal to 0 if so if there is a two
03:40:50
for example, then the radical 4, well, that is
03:40:53
the radical is equal to the right side in
03:40:55
square
03:40:57
roughly speaking, we square both
03:40:59
parts x plus 2 equals x minus 1 in
03:41:04
square
03:41:05
here is an equivalent transition but if x
03:41:10
minus 1 is greater than or equal to 0
03:41:11
then x is greater than or equal to one so x
03:41:16
greater than or equal to one x plus 2
03:41:19
equals x minus 1 squared so if x
03:41:22
greater than or equal to one and we have
03:41:25
segment from zero to one
03:41:27
then the only x that is included in
03:41:30
the segment from zero to one is x equals 1
03:41:33
so under x we ​​need one now
03:41:35
substitute and understand at what and with us
03:41:37
such x will be that is, this equation
03:41:39
It has
03:41:40
there may be many solutions, of course it is possible
03:41:42
but yes this is the level
03:41:43
she has two solutions, yes most likely
03:41:46
yes it is square but can have two
03:41:47
solutions but well, both solutions must be
03:41:51
greater than or equal to one but given
03:41:55
that x is more than one and given
03:41:58
that x is from zero to one inclusive
03:41:59
only x equals 1 can be a solution
03:42:01
let's write down the second equation
03:42:06
considering that we are looking for a root on the segment
03:42:14
from 0 to 1 root on the segment from 0 to 1
03:42:29
so given that we are looking for the root of
03:42:31
sharply to one only x equals 1
03:42:34
maybe this root is only x
03:42:37
it turns out 2 x 1 occupied x 2 equals 1
03:42:40
could this be the root
03:42:42
here of all here x is greater than 1 there
03:42:45
one two three four and so on only
03:42:46
x alone equals 1 could be it
03:42:49
root let's find out at what a
03:42:57
x equals 1 will be this root, that is, we
03:43:00
we substitute it here, that is, it is possible and yes
03:43:04
cut it there when we erected the square
03:43:06
we substitute the second into the equation
03:43:09
one yes yes let's say we'll find it we'll find it
03:43:17
at what and at what
03:43:21
and x second equal to 1 will be
03:43:26
will be the root of the equation
03:43:38
equation root of x plus 2 equals x
03:43:43
minus 1 thousand by the root of equation 2, well
03:43:47
here, in short, we substitute x equals 1 and
03:43:49
let's understand at what time this happens
03:43:51
is will be the root of 1 plus 2 equals 1
03:43:56
minus 1 that is, the root is equal to zero means
03:43:59
radicand equals zero
03:44:01
means 2 and is equal to minus 1 is equal to
03:44:05
minus one second output at a equals
03:44:10
minus 1 2 x 2 equals 1 is the root
03:44:15
equation by the way is it necessary
03:44:18
check about d is running at dc
03:44:20
so x that is 1 plus 2 times minus
03:44:23
1 second will be 00 greater than or equal to 0 to
03:44:27
here we no longer violate x minus 1
03:44:31
minus minus 1 2 more than 0 to x from zero to
03:44:35
fighter units from zero to one to
03:44:37
in short, when a is equal to minus 1 2 x 2 is equal to 1
03:44:42
is the root of the equation and all uds for
03:44:50
there, well, more precisely, that’s all it means
03:44:54
satisfies ude for so is the root
03:44:56
equations
03:44:58
let's go back to the system let's go back to
03:45:01
system
03:45:02
we get two equations
03:45:10
the equation gave us Sochi roots x 1 equals
03:45:13
a + 1 x the second turned out to be equal to one
03:45:17
when a is equal to minus 1 2 and should
03:45:25
be carried out here for
03:45:27
x plus 2 a is greater than or equal to 0 x minus a
03:45:32
greater than 0x must be from 0 to ones well
03:45:37
project two we already understood everything when
03:45:39
what and it is the root of the equation at
03:45:41
others and not let's pro x 1
03:45:44
let's understand that is, we say x 1 which
03:45:47
equals a + 1
03:45:50
is the root of the equation for a
03:45:52
satisfying the following requirement
03:45:57
firstly x plus 2 must be greater
03:45:59
or equal to 0 in the second x minus a should
03:46:06
be greater than 0 remember we said that
03:46:07
this will definitely happen, let's say
03:46:10
we didn't notice this, we'll get it again
03:46:12
now and x must be from zero to
03:46:14
units we get such a system we need it
03:46:19
solve and we will understand at what a x 1
03:46:22
is the root of the equation so under x
03:46:24
we substitute a + 1, that is, we get a +
03:46:28
1 + 2 a greater than or equal to 0 a plus 1
03:46:36
minus and greater than 0x
03:46:41
from zero to one so a + 2 is 3 a
03:46:47
large is equal to minus 10 and greater than
03:46:54
-1 a + 1 from zero to one that is
03:47:03
it turns out that what and big is equal to
03:47:05
minus 1 3 0 multiplied by what is more than
03:47:09
negative number for anything here
03:47:14
subtract one from all three sides
03:47:16
double inequality, that is, a from minus
03:47:18
one to zero we will find the suppression we will find
03:47:24
crossing we don't go crossing
03:47:33
the intersection of a is equal to minus
03:47:35
one third
03:47:36
and from the place but obviously from -1 3 to zero
03:47:39
intersections here it turns out well let's do it
03:47:47
painted, let's find the punishments
03:47:49
intersect then the number line and draw
03:47:51
-1 put a zero put minus one
03:47:56
third we need to check everything than minus
03:47:59
one third
03:48:00
and everything is in the interval from minus 1 to 0 where 2
03:48:03
shading there is the answer output at and at
03:48:09
proper segment from -1 3 to zero
03:48:14
x 1 which is equal to a + 1 is the root
03:48:18
equations but on a given interval
03:48:20
is the root of the equation
03:48:26
it remained to understand at what a x 1
03:48:31
matches with and to the old ones
03:48:32
well, considering that x 2 is a root
03:48:36
only when you see minus 1 2 for sure if
03:48:38
they coincide only at minus 1 2
03:48:40
let's check this x 1
03:48:45
matches the old iq if anything
03:48:49
occurs coincides with and to the old if
03:48:52
they are equal, that is, x x 1 this + 1 of 2
03:48:56
this one plus one matches the old x
03:49:07
2 this one turns out to be zero
03:49:10
so that is, when a is equal to zero, the roots
03:49:15
coincide nu prea equals zero 1 no root
03:49:18
in general, well, this is very 2 roots, no at all, but
03:49:23
the first one is, that is, they coincide but x 2
03:49:29
then there is no and which, when a is equal to 0, will not exist
03:49:34
That's why
03:49:36
it turns out they won't match, it doesn't matter
03:49:38
means the number line and the number line
03:49:45
A
03:49:46
and we need to apply, which means influencing
03:49:51
whether the root is x1 or x2 and so on
03:49:54
put a equal to minus 1 2 and minus 1 3 and
03:49:59
0 so minus 1 2 to minus 1 2 minus one
03:50:04
second to the left of all minus one third a little
03:50:10
more to the right 0 more to the right so let's 3
03:50:21
let's make three cells like this
03:50:23
let's look at the situation when a
03:50:31
less than -1 2 when a is exactly minus one
03:50:34
second
03:50:35
when and from minus 1 2 to minus 1 3 when
03:50:42
and equals minus 1 3
03:50:44
when a is from -1 3 to zero when a is 0
03:50:50
and when a is greater than 0 and so x 1 is
03:50:57
root of the equation for a from -1 3
03:51:00
inclusive up to 0 inclusive that is x
03:51:02
1 is the root here and it is equal to a + 1
03:51:06
and given that a is equal to minus one third
03:51:09
it is equal to minus 1 3 plus 1 that is two
03:51:11
third x 1 is the root here it is
03:51:15
equal to a + 1 always different value of a
03:51:17
here x 1 is equal to plus 1 and given that a
03:51:20
is equal to 0 it is equal to one it turns out x 1
03:51:25
in three places
03:51:26
exists and x 2 is the root
03:51:30
equations only for a equal to minus 1 2
03:51:33
x 2 is equal to one only in this case
03:51:38
obtained when a is less than 1 2 minus
03:51:42
up to 2 there are no roots at
03:51:46
exactly minus 1 2 1 root
03:51:48
with a from minus 1 2 to minus 1 3 no
03:51:51
roots for a is equal to minus 1 31 roots for
03:51:59
from -1 3 0 1 root when equal to 0 1 root
03:52:03
and at the end there are no roots for a greater than 0 and
03:52:09
Let's circle those a for which we got one
03:52:11
root
03:52:12
this is minus 1 2 minus 3 from -1 3 0
03:52:16
inclusive, that is, there is only one answer
03:52:21
the root will be if a belongs to either
03:52:25
minus 1 2 if a is equal to minus 1 2 or
03:52:29
and lies in the interval from -1 3 to zero then
03:52:34
there are two roots here, nowhere at all
03:52:35
we didn't find it, let's go over it briefly
03:52:38
the solution must be found and at which
03:52:41
the equation has exactly one root we
03:52:43
throw the right side to the left to take it out
03:52:45
ln for buying we take out saying that everyone
03:52:48
the multiplier is 0 plus 1 plus x of zero
03:52:50
to one we find x 1 with iq old here in
03:52:56
in general we begin to solve the equation we understand
03:52:57
that x is greater than or equal to one so x
03:53:00
must be in the range of zero to one and
03:53:01
however, it is no longer equal to one
03:53:02
it turns out only x is equal to 1 maybe
03:53:05
be the root of the equation here
03:53:06
we say that x equals 1 will be
03:53:08
the root of the equation is specifically in this case
03:53:10
and with others it won’t be all we return to
03:53:14
we tell the system that we have x 1 x 2
03:53:17
existing only but is
03:53:18
which are the roots of the equation only for
03:53:20
this but plus 1 plus x should be from

Description:

Если в задании 18 про параметр есть уравнение с ОДЗ, где требуется найти а, при которых будет РОВНО ОДИН КОРЕНЬ на каком-то отрезке, то скорее всего работает этот способ решения. Привет, меня зовут Евгений Пифагор, и я готовлю к ЕГЭ по математике более 10 лет. Да, можно решать ещё и графически или ещё какими-то способами, но способ из этого видео самый универсальный. Если не получается понять это видео, то возможно сначала стоит посмотреть видео про то, что такое параметр: https://www.youtube.com/watch?v=_Fn0d4gScDE 👍 ССЫЛКИ: Материалы к видео: https://vk.com/shkolapifagora?w=wall-40691695_54443 Подпишитесь: https://www.youtube.com/c/pifagor1?sub_confirmation=1 VK группа: https://vk.com/shkolapifagora Видеокурсы: https://vk.com/market-40691695 Insta: https://www.facebook.com/unsupportedbrowser 🔥 ТАЙМКОДЫ: 00:00 — Вступление 05:12 — Задача #1 19:06 — Задача #2 33:03 — Задача #3 48:19 — Задача #4 01:09:15 — Задача #5 01:31:55 — Задача #6 01:54:40 — Задача #7 02:19:10 — Задача #8 02:43:56 — Задача #9 03:10:02 — Задача #10 03:22:51 — Задача #11 03:37:50 — Задача #12 03:54:07 — Задача #13 04:15:31 — Задача

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mobile menu iconHow can I download "Я нашёл способ - убийцу параметров. Он работает" video to my phone?mobile menu icon

  • You can download a video to your smartphone using the website or the PWA application UDL Lite. It is also possible to send a download link via QR code using the UDL Helper extension.

mobile menu iconHow can I download an audio track (music) to MP3 "Я нашёл способ - убийцу параметров. Он работает"?mobile menu icon

  • The most convenient way is to use the UDL Client program, which supports converting video to MP3 format. In some cases, MP3 can also be downloaded through the UDL Helper extension.

mobile menu iconHow can I save a frame from a video "Я нашёл способ - убийцу параметров. Он работает"?mobile menu icon

  • This feature is available in the UDL Helper extension. Make sure that "Show the video snapshot button" is checked in the settings. A camera icon should appear in the lower right corner of the player to the left of the "Settings" icon. When you click on it, the current frame from the video will be saved to your computer in JPEG format.

mobile menu iconWhat's the price of all this stuff?mobile menu icon

  • It costs nothing. Our services are absolutely free for all users. There are no PRO subscriptions, no restrictions on the number or maximum length of downloaded videos.