#help-38
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I was talking about the quadratic inequality here
oh yeah
how do you know that
like
did you substitute the x with something?
i did it with 5 and -2
I phrased it a bit sloppily
But the idea is to find an interval of all x that is some distance from 2 such that the entire solution set is included
If we go from 2 to 5, that’s 3 units away
If we go from -2 to 2, that’s 4 units away
So we can only include the entire solution -2<x<5 if we’re at least 4 units away from x=2
but can you do that using the inequality of |x-2|<a please
I think that I will understand it better in that way
like +2-a<x<a+2
then I replace it
and solution one would be
+2-a<5<a+2
then I have something like -a<3<a
Second solution is
-a<-4<a ( using -2)
if I take the -a<-4 it would give me a>4
but it doesn't include that number
so I would be more likely to say that a is greater than four but it doesn't include the four
but what can I do to have the correct solution
Uhhhh ig you can just say the Union of the two solutions is the solution to |x-2|<a
🤷♂️
but is it legal to say that the union doesn't exclude the 4?
and how can you know that it achieves that
I mean
you just have an A
or the |x-2| gives you some kind of data that I'm not catching?
Anything else?
???
yeah because the two conditions for the quadratic being negative is that x should be in the interval (-2, 5)
but you have that a>4 in your equation
you're conflating x with |x-2|
(I think)
(I'm honestly not sure what you're doing)
aren't they the same x?
I just saw this video
But I still don't understand why it includes the 4 aksdhjasdhasjlfhslhfjlas
sorry
the answer cannot be greater or equal than three for the same reason
and I would think that bc of the a>4 the 4 would not be included
but it may be that because of the interval (3, infinite) it is included?
I normally would think that if I have that two answers
the interval would be something like (3, infinite) except 4
ykwim?
@burnt mulch
oh we can do a number line thing ig
I'll assume you understand where this came from
As said earlier, we need the union of these two to be the same as (-a+2, a+2)
If you have the union of some number of intervals of the form (a,b),
- The left endpoint of the union is the leftmost (or smallest) of the left endpoints of the intervals
- The right endpoint of the union is the rightmost (or largest) of the left endpoints of the intervals
So this gives us $$\begin{cases} -a+2 \leq -2 \ a+2 \geq 5 \end{cases}$$
Civil Service Pigeon
but in that case why don't you just use the a is equal or greater than zero
like, that already includes the 4
they are both sufficient ig but
the most sufficient would be a greater or equal than 3 for me
if a=3 then you have -1<x<5
in which case that's not necessary
you can have x = -1.5
wait
yk what "necessary" means here right
and why that means this
Yeah
whre it talks about |x-2|<a being necessary
ii
nvm then
sorry
my bad
I thought that the ii was necessary
haahfahafhsdfh
well now I think that I get it
._. lol
if I plug the 4 in +2-4<x<+4+2
I would have that
-2<x<6
and that includes everything but it left something in
that is the interval of (5, 6)
sorry
[5, 6)
what is right
ii. |x-2|<a must be true for -2<x<5, so a__>__4
what I'm saying
yeah yeah
iii. 2-a<x<2+a implies -2<x<5, rinse and repeat
Although the [5,6) interval is there, it is still correct
right
because it's necessary
and needs to include everything
yeah yeah
yeah
.
they prob want the complete range of values of a that work
oh so that is not the answer
$2-a \geq-2, 2+a \leq 5$
Civil Service Pigeon
no....
the answer is 8 if that's what you want to know
there's the setup
take it as you will
a<=( I dont know how to type the two of them sorry)\
a<=4
and
and a<=3
but why xd
(2-a,2+a) needs to be contained within (-2,5)
so 2-a is to the right of -2, 2+a is to the left of 5
Again, they likely want the set of all a.
DAMN
now I get it
goddamnnnn
tysm for the patience
hahaahah
now I cleared all my whys
i fkin love you man
fr
u the best
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for | z + 14 - i | <= | z - 3i |
what would be the right one
z-(-14-i) , z-(3i)
or
z-(-14+i) , z-(3i)
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is h(x) going up or down
also, in order to find if f(x) is an odd function do i need to prove that:
-f(x) = f(-x)
or
-f(-x) = f(x)?
?
thats what i thought, but you havent accounted for when x = -1.5
Why it said 2.5 on your graph
(red) vertical asymptote?
So what's wrong with x being -1.5
@minor rover
The value of h is increasing
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this is my current graph
im trying to make it look like this:
how can i move that "s" shape up but still cap it at 1?
i just want it to be more prominent
the 2 functions i have tried are tanh and erf
you just do
you move it up and move it right
and then divide by the cap it has
so by 2
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? For any x WE have that equality
You need to know like sin 2x = 2sin x cos x
And it's done
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whats the difference from the magnitude of the velocity and its displacement
In what context?
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Hey, I was wondering how to simply this. It's giving me -8/|A| but I'm not sure if this is the right result.
do you know the size of A?
Yes, my mistake. A is a 3x3 matrix.
we can work through it one part at a time
Sounds good
what is the relationship between the determinant of a matrix and the determinant of the transpose?
They're equal
yes
so then we can say the determinant is the same as here: [ |(-\frac 12 A)^{-1}| ]
pnoןɔ
Agreed
then, what is the determinant of the inverse of a matrix?
I don't know LaTeX but det (A^-1) = 1/det(A)
yes
so we can say then that this is also the same determinant: [ \frac 1{|-\frac 12 A|}]
pnoןɔ
Yeah
Then you take out the -1/2*3 because it's a 3x3 matrix right?
(-1/2)*3
to the power of
sorry
yes, then we have that this is the same: [ \frac 1{(-1/2)^3 |A|} ]
pnoןɔ
Yes
and then we just simplify the fraction
so 1/(-1/8)*|A| which equals -8/|A|?
yes
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So uuuh
How exactly am i supposed to do this when there are only two eignvalues?
How did this example get two vectors for one eigenvalue?
what equations did you get for your eigenvectors ?
For the first image? i didn't. they told me the eigenvalues were 12 and 3
eigenvectors
huh
i know they're saying the eigenvalues are 12 and 3
$Ax = \lambda x$ ?
Book Reader
ok yeah
like you tried finding the eigenvectors for lambda=3 and lambda=12 right ?
how did you attempt that ?
5 2 4
2 8 -2
4 -2 5
1 0 1
0 1 -1/2
0 0 0
eigenvector for 3 is
-1
1/2
1
?
I watched this video
https://www.youtube.com/watch?v=ChZG3uPm5uo
Here's a follow-up to the repeated eigenvalues video that I made years ago. This eigenvalue problem doesn't have a full set of eigenvectors (which is sometimes called deficient), so we need to find a generalized eigenvector to get our general solution to the system of DEs. I hope it helps!!
and apparently the second vector is k where $(A- \lambda I)k = x$ where x is the first vector
-1
1/2
1 ?
Book Reader
,w eigenvalues {{8,2,4},{2,11,-2},{4,-2,8}}
its two 12s?
pain
[-4 2 4]
[2 -1 -2]
[4 -2 4]
that's A-12I
so yeah all the rows are multiples of one another
so there's really only one equation for your eigenvectors here
2x -y -2z = 0
w/ only one equation you'd expect 2 linearly independent solutions
well the nullity of that matrix is 2 yes
well here's one way
we have 2x-y-2z = 0
we know we're gonna have 2 free variables
so let's just isolate one of the vars (which will then depend on the other 2)
so for example we get z = x - y/2
so all the solutions to this equation look like (x, y, x-y/2) [where x, y can be any real number]
these are all your eigenvectors for 12
now if you want to extract a basis from that, well you can seperate the x and y parts
(x, y, x-y/2) = x*(1, 0, 1) + y*(0, 1, -1/2)
i.e. all your eigenvectors can be generated from (1,0,1) and (0,1,-1/2)
@wraith hinge
well you want to take linearly independent ones
but as long as you respect this condition sure
okay
the whole thing I did is one way to get the linearly independent vectors decently fast
so
1 0 1 is a eigenvector
and 0 1 -1/2
yes
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What's the area of the current unshaded rectangle
The 9ft x 12ft one
Okay
Now it's saying, we're going to add a strip of a certain length to all sides of this rectangle
and the strip is a certain length such that after adding it, the area of the new rectangle is 180 ft
instead of 108
How does adding this strip affect the side lengths of the beginning rectangle?
it would increase the area yes but I was asking how it would affect the side legnths
like say you add a strip of length x
then the side length of the rectangle is no longer 9 and 12
it's what and what?
I'm asking for a specific length
not a term
the rectangle has base length 12 and side length 9
you add a strip of width x around it
you get a new rectangle
what is the base length and side length of the new rectangle
Close but no
you're moving onto a different step already but you still haven't finished this one
the strip is being added to all sides of the rectangle
I already told you 12+x and 9+x was wrong
No
the length in green is 12+x
do you see what you're missing
Why would it not make sense
you're very clearly not measuring the left side of the strip
which has length x...
so another x makes perfect sense
that's one side length
and what is the other
So your rectangle is 9 by 12
you add this strip of uniform length x,
and now it is 9+2x by 12+2x
the area was 9*12
now it is (9+2x)*(12+2x)
But also, they say this new area is 180
So
(9+2x)*(12+2x)=180
Solve for x
Solve the problem
Literally how
you didn't solve it yet
how does it seem off?
Solve for x
Okay
?
and do you know how to solve a quadratic
a+bx+cx^2
Okay
Does it make any sense to add a strip of length -12
No
It doesn't
negative lengths don't exist
so the answer is what
yes
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required to evaluate this expression. I know that 1/2 bcomes the exponent to 9 but how do I manage +1 ? or how do I convert it into a relevant log form ?
log base b of b?
=1
So you bring the exponent to the 9
So u have log3
And the 1
1 can be log10
Then u know what to do
@tribal vapor Has your question been resolved?
owhhh okay I got it, thank you very much
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Hi
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I've tried x= 70Cos(135), 70Sine(135) and y=500Cos(135), 500Sin (135). Not sure if on the right track.
*x=70Cos(45), 70Sin(45)
@wraith hinge Has your question been resolved?
I think I shld answer this cos I'm not the best at this either
Let someone who has actually properly studied this to answet
Thanks
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can someone explain to me part c?
I watched a video that solved this and I am confused when he wrote the equation for c he wrote 1+x+x^2+...+x^(2n)
why is it to the power of 2n?
because your final power to end whatever series you're working with will be even
if thats not the case, then the function isn't necessarily always positive. in fact, we positively know it isn't since taking a limit at -infinity shows that u get as a result -infinity, meaning that your function has to be negative somewhere
you need your final term to be an even power, otherwise the statement simply isn't true
makes sense?
so that equation he wrote is basically saying, this statement will always be positive so the end value will always has to be even
well we're looking at it from a more intuitive sidepoint
yea that makes sense, I think I confused myself with the last number describing the equation itself which is silly
we dont want to say "oh its always positive, so the final power has to be even!". what we're doing is "well i notice that when the last power is even, the series i have will always be positive"
oh I see
our conclusion is that its always positive, so we then connect it with the fact that it has to do with the even power at the end
what you said is also true, but its like you are using your conclusion as a given and then ending up at the fact that the last power is even
does that make sense?
yes
of course its a small difference, but a crucial one for mathematics and the logic of thinking
yup exactly
thank you for the help bill
no worries
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If
∫vdv = ∫ads
Then limits have to be same?
V velocity a acceleration
@wraith hinge Has your question been resolved?
<@&286206848099549185>
They're integrals over different variables so no
Real thanks
And another doubt
In this question
For first one they used the same
∫vdv = ∫adx
( Acceleration is in terms of displacement)
So they used the fact that at displacement 8 velocity is 4
And they did
∫vdv( limits from. 0 to 4) = ∫c/(x+4)^2 dx ( limits 0 to 8)
But but but
Velocity at 8m is 4m/s
This is fine
But what's logic behind integrating?
@wild imp this is the actual doubt
Ik the solution but logic of process isn't clear to me
Acceleration is in form of displacement but it's still acceleration
So why to integrate that
I didn't find any logical explanation other then "it's the formula just learn it"
Nope
I am confused WHY and HOW we using it
When displacement is 8m so velocity is 4
So we integrate lhs and rhs with limits 0-4 and 0-8 respectively
But why?
a = v (dv/dx) is how acceleration can be defined , rearrange
adx = vdv
dx and dv terms are change in x and v
definite integral is basically anti derivative so to "remove the rate of change" we just integrate
idk how to word it
Can you hear the voice note?
Never mind no voice note option
like velocity is rate of change in position, so its definite integral will give us the displacement of the moving object
Exactly that's my point
∫vdt = s
But that is integration of ∫vdv represent?
@vernal warren
Velocity probably
That's just change in velocity integral
So it should be velocity
Oh ok
But when it's given velocity at 8m is 4
Why we integrate lhs and rhs by 4 and 8
How do we know they are gonna be same?
A = dv/dt
Multiply and divide x
A = dv/dt x dx/dx
A = dv/dx (dx/dt)
A = v dv/dx
adx = vdv
Derived from definition of a
Yeah that i got
But how do u know limiting it to 4 and 8 will be same?
U can solve it without limit and then use v = 4 and a= 8
Both are same
solve the indefinite integral
adx = vdv
and then use v and a
U would get the lhs in terms of x , using the formula given find value of xand use that
@wraith hinge Has your question been resolved?
Oh damn
Thankss a lot man
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also need help answering my physics activities.. Thank you
@wraith hinge Has your question been resolved?
so I need to differentiate first?
what happened here? can you please explain?
@rare herald
oh the formula for ave velocity in letter a
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how do we evaluate a limit like this
what's happening in the num and what's happening in the denom
num makes it go positive and negative
denom makes it
denom goes to infinite
yep
yep
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yo
sleep deprived be like
stop saying you're stupid while im typing yep
admin help im being verbally abused
😭
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how do I find the image of this function I don't get it
when you plot this
the parabloa does not have y cordinates lower than the vertex
so the range is everything above -5/4
U don't have to plot it to see that
yeah
It's an upward parabola since the leading coefficient is positive
Plug in points for x
And see what values you get as y
And then approximate the graph when you have 5 points
Preferabble vertex
And 2 left and 2 right
they got all that yapping in the schoolbook answer when I could just look at the vertex, figure out it's the lowest point and so it's that point and all the numbers above it?
Well
The vertex isn't always the lowest point
It can be the highest
If the "a" value of the leading term (x squared) is negative
Ik, in that case it'd be all the numbers below that point including the point right
leave that to future me to suffer with, I haven't met those yet
but thanks for the warning
lmk if u got the graph^
you mean for example do x=1 to get 1^2-3*1+1, and so on until I get 5 points?
well try to get values near the vertex
your vertex was (3/2, -5/4)
1.5
so get values like 3
or 0
I'll be back in 10 minutes and try it
not so sure what the point of that is 🤔
I was studying for 50 minutes till now I need a break
i mean like getting the 5 points
oh I think that's to draw the parabola?
makes sense then
but if you just need the range then all you need is the vertex and the coefficient of a
is this true for any upward/downward parabola?
yes when x is to the second power
I see, still it would be useful to know how to draw such a parabola right?
yes obv need to know how parabolas look like
my first thought for drawing it out was to use the quadratic formula to find x1,2 but the discriminant in this case is 5, and square root of 5 doesn't really give a whole number
are you trying to draw that function?
this one
yeah, I wanna know how to do it in-case I encounter another one like that
you can do -b/2a to find the x cordinate of the vertex first
and plug that x into the original equation to get the y cordinate of the vertex
you know the y intercept is 0,1 and you can use the quadratic formula or factor to find the x intercepts
connect them together and then you should be good
I think a better way to find y cordinate of the vertex is -D/4a
D being the discriminant
wym the y intercept is 0,1
(0,1) cordinate
where do you get that information from
lmao top secret
I don't really understand why c being 1 means that y intercept is 0,1
https://www.youtube.com/watch?v=ijNMeheYiOo check this
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We will graph the following equation y=-2x^2+4x+6 in the form of y=a(x)^2+bx+c, by finding vertex=?, y-intercept=?, and x-intercept=?
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@lime vigil Has your question been resolved?
but in this case I can't use a binomial formula or factor it
and using the quadratic formula will lead me to x1,2 = (3+-√5)/2
I figured that because I got (0,1) all I needed to find was the second x for the same y, that means I already have x1 for y=1, and using x2 = -b/a - x1 I got x2 = 3, so x1 = 0 and x2 = 3 for y=1
which got me this graph
and that's correct right @plush flare
this would be correct, those are the solutions
not so sure I understand this
it is symmetric so the distance from the x cordinate of the vertex to the y intercept would be 1.5 and if you move 1.5 right from the vertex you would get 3 if that is what you mean
so at first I had gotten (0,1) which gave me one side of the parabola, to draw out the parabola I figured that all I have to do is find the second x on the same y
that works as well. it would be more accurate if you had the x intercepts, but this is a good rough sketch of how it would look
I wouldn't be able to accurately pinpoint where x1,2 = (3+-√5)/2 are by hand anyways
true
you helped me deepen my understanding of parabolas, thank you
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O centered circle with diameter AB, diameter EF such that A and E don't overlap, tangent at B intersects AE, AF at H and K relatively, P and K are midpoints of HB and BK relatively, find the configuration of diameter EF such that the area of APQ can be the smallest
cffex
then got stuck there
I think it's related to the AM GM somehow but idk
so if I'm in the correct direction $BP + BQ \geq 2 \cdot \sqrt{BP \cdot BQ}$
cffex
then find the equivalence of BP * BQ through similar triangles
thats what I thought in mind
@rain shell Has your question been resolved?
<@&286206848099549185>
Hey, I am a bit confused by the "configuration of diameter EF" part, could u pls explain more clear?
I meant find the position of the diameter EF
hmm
so like rotate around the circle, at which rotation would have the triangle's area be the smallest
Triangle APQ?
Im sorry I dont think I understand how EF affects the area of APQ at all
the tangent of B intersects AE, AF at H and K
P is the mid point of HB
and Q is the mid point of BK
Ahh I see
Yeah that could work
Try drawing it out
I suspect there could be a smaller one tho
which tool are you using?
Geogebra
Alr
Lets try to look for a pattern here
Since we can only manipulate the position of EF, and the Ar(APQ) is depended on EF and AB(cuz everything else indirectly follows EF)
yea
here is the formula for it
What if you draw EF really close to AB, almost overlapping but not
@rain shell is there a way you can share this drawing to me like a link or smth? i wanna open it in Geogebra myself
wait a minute
Ohh i get it
the closer E is to A, the larger the area of APQ
its approaching infinty
yes
So lets do the opposite
whats the farthest
I feel like perpendicular is the farthest we can go
yeah I tested
it is
it AQP becomes an isosceles triangle at that point
which we can prove
we just need a reason why at that point the area is the smallest
Did you prove the isosceles triangle using similarity
nope
congruency
oh
actually congruency and then a few more steps
Did you just measure the angles?
no
Wait we wanna prove that the area is smallest when its perpendicular, right?
we want to prove at what rotation EF makes the smallest area
so we cant just jump to perpendicular yet
yea
1/2 * ab*bp+bq
cffex
fancy text
lol
So, when the angle EOB increases, angle Q of the triangle decreases
meaning BQ increases
Hence area increases
we just gotta prove that value of Angle AQP is least when EOB = 90 deg
actually
the more EOB increase, the closer it is that PQA approach a right angle
so the more EOB decrease, angle Q of the triangle decrease
oh its F
ah
i overwrote the geogebra link
are we allowed to measure any angle using the measure feature in Geogebra
no we cant measure stuff
lol take ur time
uh huh
yes
and so is QCD
yes
Now, using trigonometry, we can prove that the hypotenuse of Triangle DCQ increases when AOE increases
but we arent done yet cuz it also decreases when the angle decreases
we can prove that the hypo of triangle ABP also inc/dec depending on angle
and using sin and cos, we can find that the least value would be 90 deg i.e 1 and 0
Closed by @rain shell
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Sorry my internet went out
@rain shell
Hypo of DCQ is part of side of APQ
According to herons formula side of triangle affects area
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well x must include 2^3 * 3 as its factors
y must include 2^? * 3^2 where ? is either 1 or 2
z must include 5^2 * 2^? where ? is either 1 or 2 too
that's all i got in my head so you have at least 4 triplets
not sure what degrees of freedom you can have for x, if any
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One hundred reservations are taken for a cruise on a ship that has only 95 cabins. If experience shows that only 90% of the people making such reservations show up. What is the probability that everyone who shows up has a cabin?
Derivative
hmm
$\sum_{x=0}^{95} \binom{100}{x} \times (0.9)^x \times (0.1)^{100-x}$
Derivative
because it says the probability that everyone that shows up has a cabin
so it can't be from 96 to 100 because then that would be the probability of overbooking
in total 100 people have booked
chances of showing up is 90%
Yes that's right assuming you mean each individual person has a 90% chance
yes
i will put that answer
i think it is right because it says that 90% of the people show up
and the average is np = 90
so on average 90 people will show up, but sometimes more sometimes less
now, what i will do, is estimate this answer, cuz i cant use a binomial table since n is too large
i will estimate using normal distribution
right now, i get 0.9664 (96.64%) chance
which is pretty reasonable
.close
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how ? 💀
Couldn't you multiply numerator and denominator by what's in the numerator already to simplify
That gets rid of the square root up top and you use difference of squares in the denominator
yeah i did that
but now am lost
Send what you got doing this
I can’t be bothered to do it but I’ll help past that stage
Ping me with response
@wraith hinge i got this
Hm
I mean
If you expand the bracket on the top and then split the fractions the (x+1) terms will become a bit nicer
Although I’m not sure how beneficial that will be for dealing with the 2X part
uhh but the 2x
yes
is there a scope for beta function
Do it and see if there’s a nice substitute that could work
@ancient shadow Has your question been resolved?
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We can spot that the equations for V and B are very similar, and that by moving 25x across to the LHS, the RHS will match
Basically our goal is to build an equation where the RHS is the same as the RHS for V. So that then we get that V = LHS
Oh
@frosty heron Has your question been resolved?
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Why is a function not differentiable at a "corner" or cusp?
what should the derivative at that point be?
0?
if you come from the left you get a different slope than from the right
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how do i find the integral of this: sqrt(x^4 +2x^2+1)
i dont khow how to start
Try factorising the thing inside the square root. If it's hard to see, try the substitution y = x^2 to help you see it.
Find a way to put it into the form $\sqrt{1+u^2}$
so x* ( x^2+2) +1?
SWR
i do nto know how
seems like square of a sum
can u help me work it out
i do not want the answer as.much as i wanna know how to integerte it
i did this
i dont think that'll help us here
Do you know how to write a polynomial like (ax+b)²+c ?
I can show how to do it in another example so you can use it in this problem, is it fine?
completeling the square?
i know how yes
ok then try doing that with x^4+2x^2+1
wait no
it will be
(x^2 + 1 )^2
that is indeed correct
how would i integrate (x^2 + 1 )^2
square root of square of (x^2+1)
np ^_^
completing the squares looks like a useful method
but when do i know when to use it
there are some specific equations like x²+2x+1 or x²+4x+4
this wont work if its not a square of a sum
(ax+b)²+c
the one that was given was a square of a sum (c=0)
completing the squares is really helpful when finding the reverse functions
In some cases like this in integrating too
i dont understand this
can u please give an exmaple
lets say x²+4x+4
its just (x+2)²
but in the case of x²+4x+6
its (x+2)²+2
this is the sum of a square
What im trying to say is
we would've taken another road if it was something like squareroot((x+1)²+2) since we cant get this out of the square root
thanks alot
sorry but
can i write √(1+4x^2) a 1+2x ?
i cant imagine am struggling with algebra
no you cant
since (1+2x)²=1+4x+4x²
i know you'll fix the problem, i feel like you only need more practice
my test is tmr
and its 12 am for me
starting to lose hope
but ill push forward
thank you
sorry another question 😭
go for it
√(2+4x+4x²)
i wanna integrate that
using completing of squares?
i do (2x+2)^2
i think yes
thats incorrect
why
2
mhm
4(x+1)²-2
maybe we can do an u subtitution to get rid of that -2
no idea
if that x² at the beginning was an x, then yes we would've been able to take the integral
nah i quit
You're gonna have to let x = 1/2 sec(x)
oh i see
Don't worry
Everybody hates them
Every time I have to do a trig sub my will to live decreases
always forget trig sub exists ngl
Peter griffin no likey
understandable have a nice day sir
@fossil cobalt Has your question been resolved?
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Let ( f ) : ( \left(-\frac{1}{2}, +\infty\right) \to \mathbb{R} ):
[
f(x) =
\begin{cases}
\frac{\ln(2x+1) + \cos(x^2) - 2x -1}{x} & \text{if } x \neq 0, \
0 & \text{if } x = 0.
\end{cases}
]
Find, if it exists, ( f'(0) ).
milanesa de pollo
You first need to see if f is continuous at x = 0
You may use L'Hopital quickly for this one to check
Closed by @paper willow
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the integrand is correct, but your bounds are not
that works
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I am confused on why my N doesn’t work
epsilon is .001
Oh it should be 1/1000
But it still doesn’t work
I’m assuming I can’t make it 1/N
I changed it to 35/N and it works
.close
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I have no idea what this is saying. Why do I need axiom of choice to say cartesian product would be non-empty, and what does this H function have to do with it?
the almighty has a doubt ⚔️
fix it
I'll be disappearing soon, so may ask again later.
@kindred pier Has your question been resolved?
Someone smart please help me
@kindred pier Has your question been resolved?
In regular mathematics terms, H is an I-indexed family of non-empty sets.
The cartesian product of (H_i)_{i \in I} is the set of all (h_i)_{i \in I} for which h_i \in H_i.
So saying that for any such choice of H the cartesian product is non-empty is essentially saying that every family of non-empty sets has a choice function, which is probably the most common formulation of AC.
So I need to AC to say Cartesian product of non empty sets is non empty? What's wrong with $\exists (x\in X) \exists (y\in Y)\to (x,y)\in X\times Y$?
SWR
That only proves that the cartesian product of two nonempty sets is nonempty
By induction you may also prove that the cartesian product of any finite family of nonempty sets is nonempty
The statement equivalent to AC talks about all families though
But isn't that what the first sentence is saying in my image? "The Cartesian product of non empty sets is always non empty". They're making it sound like I need AC to be allowed to say that
cartesian product here refers to the general version (of arbitrary families of sets), not the binary product
I.e. ∏, not ×
I don't think i follow. 
What's the first one?
Second sentence here, though I'm sure the book must include a similar definition earlier in the text if they're talking about the cartesian product formulation of AC
I'll have to review the book but I did not see that definition
Oh here we go. I never read this section
Okay that probably answers all of my doubts

