#help-27
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you prob fucked something up with your signs
@summer summit Has your question been resolved?
i sent gpt a photo of this and it said -16 as well (yes i know gpt isnt trustworthy but i got the same)
!nogpt
did i switch the bounds?
yes i know bro
lol
from -2 to 0 should be -2x+x^2-2
yeah i switched the bounds of the integral it should be the opposite
so this is wrong?
yes
lmao
i would assume for a competition solely on integrals you would want the answers to be right.
Which one?
the answer is correct, the derivation is just wrong
yeah thats what i meant
can you give the full context?
like which college?
I guess? I just want the name of the bee.
literally just the answers no work
depaul university; its their own thing, only for undergrads
Ok
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How do I find for a symmetric A an orthogonal matrix Q such that $Q^T A Q = diag(A_1, A_2, \dots, A_k)$, where $A_k$ is a 1x1 or 2x2 matrix?
This has something to do with spectral theorem
Lambda
Let's say a matrix like this one
What I really need is the name of the process I need to use, I can look it up on youtube, but don't know what phrase to use
(orthogonal) diagonalization
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Is there any reason why a cube forms when I display a set and it's subsets like this??
The number of vertices in an n dimensional "cube" is 2^n
same thing as the the number of subsets
oh interesting
ive never thought of that or came across it
i appreciate it
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g(x) = 10sin(6x) +20
but when im solving with calculator im gettting sin6x = -4/5
6x = -0.927
x = -0.155
since sin is periodic i added pi, but thats only getting me 2.987
which is not in the domain of x
so what am i doing wrong
this is what the ms says but im still lost
,w arcsin(-4/5) / 6
this looks right
you added after dividing by 6
,tex .reflect trig/sin
riemann
the one on the right
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My professor presented orthogonal trajectories in a very weird way.
He said that for an equation F(x, y, c) = 0, with c as a constant, you can find orthogonal trajectories to it. He made it so that he could explain how to find orthogonal trajectory for x^2 - y^2 = C
The point I didn't get was this weird notation of F(x, y, c) = 0.
If you say there are three inputs for one output, then I imagine this function could be modeled in the fourth dimension (i.e., F(x, y, c) = w). Ignoring the fact that c was included, then I could imagine that our function is such as F(x, y) = z. So then what he meant by F = 0, is that the z values are zero? That is confusing.
the notation is a bit ... confusing albeit standard, ill give you that
You said it yourself. C is a constant. You have 2 variables in total (including output and input vars) so your function will be modeled in the 2nd dimension. Your prof's notation is a bit odd but not inherently wrong.
So, F = 0, essentially stands out for z = 0 in this case?
I agree with both of you this notation is weird smh.
How are you usually presented with this concept then, if you could please tell me ?
No not really... its a bit confusing to try and "reverse engineer" your profs notation
Want me to give you the way he presented this?
if we take function f(x,y) = x^2 - y^2, the function defines an infinite set of curves in the third dimensions, in which x^2 - y^2 = C
is a specific curved for the specific chosen constant C.
when trying to look for an orthogonal trajectory one usually rewrites it as x^2 - y^2 - c = 0.
but since the process of finding orthogonal trajectory is by differentiation, the constant doesn't really matter that much
personally, I've never seen it noted as if C is an extra input.
its not really a "third" input as C specifies a specific 2d curve in a 3d space, in this example at least
its been a while since i tackled this though i might be rusty
Right! So what you are saying makes a lot more sense tbh.
In such a case, the function could just be defined as F(x, y) = c, and thus F is some specific function for that c value
It's fine you've explained so well!
I don't know if this helps at all, but he presented it like this
If we have a family of curves C1, C2, … , Cn and another curve C, we say that C is orthogonal to this family if it is orthogonal (perpendicular) to every curve in the family.
Let F(x, y, C) = 0 be the equation of a family of curves. By differentiating and eliminating the parameter C, we obtain the differential equation of the family.
If F(x ,y ,y′) = 0 is the differential equation of the family, then:
F(x ,y ,−1/y′) = 0 will be the differential equation of the orthogonal trajectories. Solving this last equation gives the orthogonal trajectories.
Two families of curves are said to be mutually orthogonal if each curve in one family is orthogonal to every curve in the other. Such families form an orthogonal net.
well, thank you! @gaunt quiver @midnight echo
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Need help being able to quickly decipher these type of problems idk why but looking at them always confuses me and i have to really meditate on understanding what side of the z score im calculating for. i know too that i can't really "read" it and think thats part of why im struggling.
@supple light Has your question been resolved?
I need help solving the socnd part as well i thought i understood .
What i did was solved for the z score of 209.8
209.8-218.6 (mue) / standard error which is 81.6/squareroot of 169
i ended up with -8.8/6.276923077 = -1.401960784
i inserted that into the normalcdf function as my lower limit
but got the wrong answer
<@&286206848099549185>
CLT
right thats the subject
Did you get the first part right?
yessir
Cause that doesn't apply clt, it's just straight normal
Alright
Well your initial std is 81.6, to apply the CLT compresson you divide it by sqrt(169)
i showed my work above just unsure what i missed
for the standard error yes i did that
i got 6.276923077 when i did
then to calculate the z score i took that qoutient to dived -8.8 which was the difference between x and the mean
then i plugged that as my lower limit in normalcdf
i wasn't sure if i was upposed to use a standad distribution or not but i tried both. . 9966492 for when i kept the normal distribution and .1595055 for when i used standard 0 and 1 for the mean and SD which seemed more accurate given the mean being 209.8
Both are wrong
i saw lol
You are supposed to use the standard normal distribution though
is normalccdf the wrong function?
The whole point of your transformation and z score (-1.402) is to transform your problem to one with a mean of zero and std of 1
what langauge & inputs?
im not sure what you mean but i'm using a ti 84 if that helps
Looks correct, and it outputs?
when i re entered i got .9195273
yeah thats right lmao
okay great yea i used ans as my input intially and it populated something else glad my math was decent thank you !
the question doesnt specify rounding so i was trying to avoid typing all that up but thanks again
Np. You could have also used (209.8, 1e99,218.6 ,6.2769...)
Basically instead of having to standardize, you wouldve just modified the std according to CLT and chucked the values in directly
Which in natural language would be "The prob of being between 209 and pinf with a mean of 218.6 and std of 6.2769"
@supple light Has your question been resolved?
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I got a question 🙂
The area of a shape is 6x*2-2x
one side length is 2x
and is the other one
the shape is a square
What is the question?
.
I said it
I don't see any question mark, which usually denotes a question 😅
Mmh alright
The area of a square is 6x*2-2x
the one side length is givin as 2x
find the missing side length
I cant draw it out bc im on computer
IT make sense?
<@&286206848099549185>
Yeah all good
Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.
lemme try
im on computer tho
it shows a square right
and one side is labelled
2x
and the total area of the square is 6x squared -2x
?
...
if it's a square all sides should be equal
well maybe its just a shape
yea prob
It said shape on the question
the picture showed smth close to a circle tho
I guess it threw me off
Lets call it a rectangle
imma go to bed this taking so long and im tired
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$M$ is a subvariety of dimension $p$ of $\mathb{R}^n$.
\ \
For any $a$ of $M$, there exists an open $U$ of $\mathbb{R}^n$ containing $a$ and a submersion $g \colon U \to \mathbb{R}^{n-p}$ such that $U \cap M = g^{-1}(0)$.
\ \
For any $a$ of $M$, there exists an open $U$ of $\mathbb{R}^n$ containing $a$, an open $\Omega$ of $\mathbb{R}^p$ containing $0$, and an application $h \colon \Omega \to \mathbb{R}^n$ which is both an immersion in $\mathbb{R}^n$ and a homeomorphism of $\Omega$ onto $U \cap M$.
\ \
For any $a$ of $M$, there exists an open $U$ of $\mathbb{R}^n$ containing $a$, an open $V$ of $\mathbb{R}^p$ containing $(a_1, \dots, a_p)$ and a smooth application $G$ from $V$ into $\mathbb{R}^{n-p}$ such that, after any permutation of coordinates, $U \cap M$ is equal to the graph of $G$.
tm
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between these 4 equivalences, which is the one most often used to show that a set is a sub manifold?
bc i want to show that the torus defined by \ $T^n = \left{ z \in \mathbb{C}^n , \ |z_1|^2 =…=|z_n|^2 =1 \right}$ is a sub manifold
tm
@grand warren Has your question been resolved?
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Part (b)
1 moment I will draw a diagram
If im not mistaken they look like this
Line m can be rewritten into y = mx+c
-4 = (3/4)(-1) + c
c = -13/4
y = 3x/4 - 13/4
So the slopes of the other lines are also 3/4
Im not really sure what to do next though
Equation of the tangent line is gonna be y = (3/4)x+c
so, for some constants c1 and c2, the line is gonna be r distance away from the center, and for those values of c, the line would be a tangent
So what you need to do is find the values of c such that the distance between the line and the center of the circle is same as the radius of the circle
Im guessing we using |ax + by - c|/sqrt(a^2 + b^2)?
With (3, -1) as x and y
yea
your slope is flipped, it should be 4/3
Oh oops! Thanks 😅
I was always a bit confused about this formula, like I kinda understand it but not 100%. If we just forget about the original question for 1 second...
Just so that I understand, which corresponds to which
Where is the point (x, y)
And which line is ax + by + c
And is the circle even necessary? or can we use this formula without it
nah circle is not necessary
So this equation is for finding the distance between a point and a line, right?
Aka the green line in this case
yea
but tbh, if I were asked a figure for the formula, I'd draw something like this. Like that circle thing is unrelated to the stuff in the formula
npnp
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Help please I can't find X
38?
angle x is sharing same arc with the angle CAO=76
Yes
i just know that x is half of the arc angle
Back sorry wifi issues
I got 76 and I thought it was equal to x but its jot
Not
BUT ITS NOT LIKE
It's not opposite it
It's not like this
Nvm I googled it
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I tried doing this question using both separable and linear DE for practice but I’m messing up my signs somewhere
$$40+Ce^{-\frac{t}{20}}$$ vs $$40-Ce^{-\frac{t}{20}}$$
Thyroxine
also for the first part ignore x, its t
what is your problem
$\frac{dy}{dx}=2-\frac{y}{20}$
devthemasked
Is this your question?
yeah
the step where you raised both sides with base e
e^(-x+c)≠e^(-x)+e^c
the e^-x/20 in the first way?
no
okay tyy
@ebon rose Has your question been resolved?
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i just have a question abt this image
so
a being a vector has a1 and a2 coordinates and b being a vector has b1 and b2 coordinates
easy simple whatever
now geometrically it tells me to visualise it using head to tail rule
but in the graph it is kind of evident that a1 is the same as b1
however it isn't in the question?
slightly confusing
b1 and b2 aren't coordinates
It's the magnitude and direction of the vector
So b1=3 means that vectors b has an x component that is 3 units long
And b2=-2 means that the vector b2 has a y component of -2 (2 units down)
So b1 and b2 can easily be read as 3 units right 2 units down
interesting
Very interesting
I have a good note that explains it if you'd be fine with me sending it
Sure
@sand isle Has your question been resolved?
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Got a question
whats your question
,rccw
I just don’t know what to do here
Yea it’s 18x^2+54x
no, i said in general.
Like simplified
no.
forget about this problem
let's say you have a box with a known length, width and height
how do you find its volume
yes, V = l * w * h
Yea
So you times L and H to get the total of them, then see the difference between the volume and L*H
no you are overthinking it
And that would be W?
and not the difference
take this formula, and:
- replace V with 18x^2+54x
- replace l by 6x
- replace h by 3
DO NOT simplify
show what you get
18x^2+54x= 6x* w * 3
I symplified
And got the right side to be 18x*width
And ik to get width im going to have to divide the left side by the right side
Let me do that not
Now
18x^2+ 54x
18x
Divide them
And let me see what I whet
Get
I got x+3
Yep correct
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How do i do this with Cauchy
I did it with AM-GM but i know there is a Cauchy solution but i cannot seem to find a way to make the lhs into a product of sums
x, y, z > 0
Did you try (y, z, x) and (1/x, 1/y, 1/z)
@upbeat stone Has your question been resolved?
I thought about it but there are many other terms other than the 3 on lhs so idk how it helps
@upbeat stone Has your question been resolved?
@upbeat stone Has your question been resolved?
did you try it
Yeah but i just noticed i forgot to square the sum of the products of the elements of the sequences and that the remaining terms might cancel in both sides 😳
@upbeat stone Has your question been resolved?
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Hi all, I have a math assignment in Set Theory, it goes as follows:
If (G, *) is a group and a,b,c in G, solve the following equations while listing the characteristics which are used:
a) x * a * b * x * c = b * x * a (under the assumption that (G, *) is an Abelian Group)
b) a * x * b * c * x = a * b * x (under the assumption that (G, *) is not an Abelian Group)
For a), I got that both sides are equal when x = c^(-1); for b), I got that both sides are equal if and only if b and c are commutative (and x = c^(-1) here too)
Meaning, that for a) both sides are indeed equal, and for b), they are not unless b and c are commutative.
Did I do this correctly?
And if there's any more information I need to provide, please do let me know. I'm new to discrete mathematics.
Stating that "both sides are equal" is a strange thing to do. Of course both sides are equal. The question starts by telling you they are.
Your solution to a) is good.
You don't really have a solution to b) here.
Assume nothing is commutative. What does the equation simplify to?
For b) I got it down to c^(-1) * b = b * c^(-1), and since it's not an Abelian group, I assume that this is not a solution since the operation is not commutative?
I could also rewrite my entire solution in English so it's easier to read and just send it here, if that'll help anything
I can get it down to xbc = b
Just by multiplying a few inverses in on the left or right
Other than rearranging things, this is as simple as we can do
There's really not a lot of flexibility to general groups. All we can really do is take a off the left and take x off the right
I defined y even though the operation is not commutative in this context, so y = b * x can't be applied to both x * b and b * x
Yeah, I understand; although the thing that kind of stumps me is what they want me to list whilst I'm doing this; what kind of characteristics
I like that you're saying what you're multiplying by. Common terms are "left-multiply" and "right-multiply"
When the term ends up on the left or right of both sides
You may want to include that x•x^-1 = e, the identity. That e•x = x. You use these a few times without mentioning, maybe they want that
Like this, you mean?
or is it better to write forall k in G, k * e = k since I'm doing c * e and x * e here (in order to not write ... * e = ... every single time?)
So it is just sufficient to write one example of it
Anyway, thank you, that's all 👍
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for this proof can I just assume x and y are irrational where is the additive inverse of x. the sum of these two is 0 which is not irrational so it is false
its saying always, so simply giving a counterexample is enough
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i understant how to graph the region and how to get the limits of integration, but can someone pls explain how they got the fuction f(y,z) = 2
hmm ok
@lyric hornet can i ask u another question?
how did they get the f(x,y) for this graph the 'height' are u different fuctions?
hmm my explanation wasn't so ideal... that's my bad, but the reason there's a y now is because the height is different at different y-values
at any given (y,z) the "x-height" was always 2
so we intergrated over that
but now any (y,z) changes as y does because of the way we constructed our shape
@smoky sentinel Has your question been resolved?
hmm ok
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so i got x - x^2/2 + x^3/3 -x^4/4
but now what
deepseek did this but i dont quite understand how it got that
can you write the general term for the sum?
this thing right?
that doesn't seem to be the correct formula for this sum
i would right the general term by looking at the pattern here right @acoustic leaf
(ignoring that deepseek found it)
write*
yes, or derive it from a known series
so i take the absolute value which gives me x^(n+1)/n
it doesn't matter, use whichever one gives a simpler formula
okay so (-1)^(n+1)*(x^n)/n
sure
is there any aspect of the series we can use to get an easy error bound?
what error bound theorems do you know?
alternating series theorem
that works
well we want R_N < 0.001 so we should have R_N <= a_(N+1) < 0.001
so if we can get our upper bound on R_N less than 0.001 then R_N will definitely be less than 0.001
ok...how do we apply this here
so you want the error on your sum to be less than 0.001
you know that the error on your sum is at most the next term in the series
so if you can find an N such that the next term in the series (after N) is less than 0.001, then the remainder (which is smaller) is also less than 0.001
it should be in absolute values
oh right
so when you say "error on my sum" you mean the difference between the approximated value and the exact value
we want to know how far that is from ln(1.35)?
well can i omit the absolute value if i "get rid of" the (-1)^n+1
well that's what you get when you apply the abs val, yes
yes, we want it to be less than 0.001 away
hmm. okay so the point of doing the maclaurin polynomial was to recognize a pattern for the general series. now using the absolute value of that series, we plug in n values until we get a number less than 0.001
so if n = 4
i get 0.001050 which still > 0.001
if n = 5
i get 3.06377E^-4(which is 0.0003 i think) which is < 0.001
so the smallest n value that can satisfy the error bound is n = 5
is my assessment correct? is that how i approach these problems?
that would imply that if you were to sum 5 terms of the maclaurin polynomial it would be good to 3 decimal places
im missing your point
just interpreting your result
so...am i on the nose here
seems fine to me
okay sick
can i bother you with one more problem similar to this
what is it?
lmk if my work doesnt make sense im the only one who can understand it tbh
but im pretty sure the pattern is x - x^2/6
wait ^3 nvm
sin(x) has a pretty famous maclaurin series
0 + x + -0x^2 -x^3/6
ugh
there
are 0s for every sin so idk whether to make it - or +
well it doesn't really matter for the 0's
im kinda struggling with the pattern: x - x^3/3!
tbh this is one that's worth memorizing
would it be cheating if i just googled the series expansion for it lmao
well the pattern for the derivatives is fairly straightforward, nut making a formula is a bit tricky
it jumps from x^1 to x^3
so i don't think there's anything wrong with just looking up the formula here
that's just a way of getting only odd numbers
yes, that's how they put the expansion into a formula
ok so lets go with that
so the procedure from here is very similar to the previous
??
the only value that works here is 2
the n you solve for with the alternating series test is the number of terms, not necessarily the degree
so that means i need a different series
no
err general formula
just need to interpret the n value correctly
so if you plug in n = 2, then that is the maximum error if the n = 2 term is the first term not summed
so the highest term is the n = 1 term
but what is the power of x for n = 1?
3
i need it to equal 1?
since the first term is x^1/1!
we start indexing from 1 right
for this formula we should start indexing from 0, since plugging in n = 0 gives you x
if you wanted to index from 1 you would use 2n - 1 instead
okay so why isnt 2n+1 working
the question is asking for the degree of the maclaurin polynomial
you need to be able to convert between a value of n and the degree of the corresponding polynomial
hm and degree is different from nth term
well how do i find that
right
so what do i do
so if you have a value of n corresponding to an exponent, and a formula for the exponent corresponding to that value of n...
youre talking about a(n+1)?
so my a(n) is 2n+1
so a(n+1) would be 2(n+1)+1
is that wym
so the first value you plugged in to the sequence that works is 2
so that's you're n + 1 right
i suppose so
so then the highest power of x in the sequence is corresponding to n = 1, so x^(2n + 1) = x^(2*1 + 1)...
ohhhhh oh my god i finally get it
it only fulfills the condition when its on x^3
which means third degree
this whole time i kept associating it with the n value
ty
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how do i get that f is linear by subbing x=a+b on part e?
im p sure its related to theorem 3.8 at the top
so what we know:
f is odd
f(0)=0
f(x+y)=f(x)+f(y)
oh wait i forgot these have a solution at the bottom
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@inner ibex Has your question been resolved?
the direction vector of your line should be:
- perpendicular to the direction vector of the given line
- parallel to the yz plane -- and thus perpendicular to i
do you understand why this is so?
so i only care about
j and k
ig in this case that is true, but
here is a more general question
how do you find a vector that is perpendicular to two given vectors?
reread what im asking carefully
uh
u use vector equation
like
idk how to explain it
so first
i would find the vector where the dot producti s 0
i think you're overthinking it then.
the cross product is what i was looking for from you.
my teacher said we learn that after the holidays
oh
whats the hard way?
the "let your vector be yj + zk and declare it perpendicular to 2j-k and solve for y and z manually" way
which means your shortcut of "oh the i component is automatically 0" is justified
oh i think thats what i was triyng to explain
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whenever
@restive river Has your question been resolved?
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fauji
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x = ± √(8) * i , ± √(2) the sum of |x|^2 is?
I wrote it as -8+(-8)+2+2= -12 which is wrong
this is not readable..
$|a+bi|=\sqrt{a^2+b^2}$
yoboiqimmah
Oooohhh I got it!
I just presumed that the mod just mean for changing ng -ve to +ve
I am an idiot
Thanks
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nah it isn't obvious taking absolute value of a complex number
But it should have been, I was literally doing a complex number question
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are these two answers the same answer? they just got switched up in the exclude... is it allowed to exclude with - ?
so it would be the same? just so my prof. doesnt blame me haha
give me a second, ill send a pic
ℝ𝕚𝕥𝕧𝕚𝕜
so ya, it is the same answer
you can use \frac{a}{b} btw would be better imo
ohh, i didn't know that
i dont know how to convert...
ohh
like
is it okay to leave the answer with the opposite operators?
or do i have to convert it
depends
generally, you have to convert it
hmm okay
so in the numerator
is this correct?
we have -4x + y
ye
maybe multiplying by -1/-1 would be a bit better/easier imo
not really
do you know how to take things common in an equation?
not sure haha
maybe
ya, but not exatly
you tried factoring here and did it wrongly
you can continue from here multiply by -1/-1
you can do this also
what do you mean by -1/-1
could you paint me that or smth haha
i have to visually see this 🥲
one sec
$$ \frac{-1}{-1} * \frac{-4x+y}{-2x^2 + 3y^2} $$
ℝ𝕚𝕥𝕧𝕚𝕜
you did not change the signs
that was the problem
when you multiply -1 with (-4x + y)
you get 4x-y
when you multiply you will get the answer
i was talking about the way i told u
yeye haha 🙂
you can multiply and divide anything by the same thing
so if you have any fraction
$$\frac{a}{b}$$
ℝ𝕚𝕥𝕧𝕚𝕜
you can multiple it and divide it by any number and it will still be equal to a/b
ohh okay, so if the bottom part of the / cant be done cuz of the - then i have to straight on go with the +?
i didnt understand
wdym
you mean -4x?
ye -4x
wdym
instead of - go with +?
no
go with - only
but dont write 4x
one sec wait
$$ \frac{-4x+y}{-2x^2+3y^2} = \frac{-1}{-1} * \frac{-4x+y}{-2x^2+3y^2} = \frac{4x-y}{2x^2-3y^2}$$
ℝ𝕚𝕥𝕧𝕚𝕜
thats how u do it
would prefer using brackets when multiplying these
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We consider x and y two real numbers. Prove (using scalar product) that x+y < (1+x²)(1+y²)
Lesser or equal
maybe
But how to remove the absolute value
Ok
So with absolute value it’s correct ?
Thank you
wait a second
i read it wrong sorry
x+y <= |x+y|
@cinder moss if its true for abs it should be true without abs
Im stuck here
$x+y \leq (x^2+1)\cdot (y^2+1)$ are you sure its less or equal?
parabolicinsanity
and not just less?
what can you say about |x+y| vs |x+y|^2
Well it’s not always true that |x+y|² is greater than |x+y|
when is it not
When it’s a whole number ?
0.5 is not a whole number
When it’s less than 1
i guess equality can hold
$|x+y|^2=(x+y)^2\geq x+y$ maybe this is the way
parabolicinsanity
Well 1+x² and 1+y² are both greater than 1 so their product is also greater than 1
the last inequality isnt always true which is the problem here
(x+y)² is less than x+y when the latter is less than 1
The right side is greater than 1
So if x+y is greater than 1 then the inequality is correct
yes
But how to prove it when x+y<1 ?
x+y <= 1 <= (1+x^2)(1+y^2)
x+y <= (x+y)^2 <= (1+x^2)(1+y^2)
those are the two inequalities you need
Thank you so much
Not only did you help me but you didn’t give me the answer straight away and im thankful for that
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isnt the denominator (z-i)^2 (z+i)^2 ?
oop yes
parabolicinsanity
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I cannot, for the life of me, understand this method of getting the proof. please help.
ping pls
@hardy tendon Has your question been resolved?
Which part is the problem
the red is what i cant get, but it is to prove that the top line is equal to the bottom line
Try to convert tan sec cosec in sin and cos
i dont follow..
???
tan sec cosec? where is that?
I meant like in the second expression
Convert tanA into sinA and cosA
Similarly with sec and cosecA
yeah thats done its the ones in red that i cant get
the sin actually worked idk how i didnt get that @fickle slate
so did the cos
/sin
thank you so much i understand how to do the proof but my mind was mashed by the way its asked in this webwork
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Tangents confuse me
Take derivative to find tangent slope
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
I have I found that -π/2 + sin(xo) = -cos(xo)•(π/2) + xo•cos(xo)
How do I continue
@eternal aspen Has your question been resolved?
I think move everything to one side and treat it as f(x_0) = 0. plug in for a few convenient values of x_0, I think you can get both solutions by just guess and checking?
Then take derivative to show behavior of the graph. itll only have one critical between [0, pi], and if there were a another solution, that would imply the existence of a second critical point in that domain
I think this seems right
There's a critical point between every two roots due to MVT
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how can I finish the equation?
sry I already asked before but the request expired
whyd you multiply this
i multiplied both sides by this
to cancel with the numerator on the right of the equation
so then I used (a-b) x (a+b) = a^2 + b^2
im not convinced you're writing stuff very nicely
if that makes sense, correct me if im wrong
im massively confused
sorry, on the second line I found the common denominator for the left side of the equation
then I factored (x2 - roo2) in front
I can rewrite it if it's difficult to read?
whered the thing disappear
(a-b) x (a+b)
I used this formula with the term next to it
idk if it was called term, I meant with this
turns into x^2 - 2 under the cube root, no?
holy shit okay
you need to work on showing your work properly
but yeah this is fine
good to know ty
so with that I was stuck at this
i don't even know if I wrote it correctly, like does the cube root fall or stay there above x^2 - 2?
what?
anyway here letting the $x^2-2$ be $z$, you have $z z^{\frac13}$
Percy
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When I differentiate the lifetime utility expression with respect to C1
Does the 1/1+delta disappear
Assuming that delta is a constant (or at least wrt C1), you multiply the derivative of sqrt{C1} by 1/(1 + delta) 
(Also hiii
)
Hellooo
O ok had to check I ain’t crazy
How ru chartbit
I’m good, been a bit busy but for right now, I’m chilling at least 
How about you? 
Awwww, happy you’re good
hope everything stays good (though I’m sure I’ll still see you
)
Yeah 🫡
@lofty monolith Has your question been resolved?
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This should be a quick one, I dont trust myself so I ask: Is this correct?
yw
Have a nice day
thnx u 2
Yeatte
It's .close but it needs to be op who does it
mm i c
Oh wait before you leave, how do I get alpha?
in this case, it would be arccos( the formula you had before)
$\arccos(\frac{yy-xx-length^2}{-2xy}) = \alpha$
I hope its a build in function (I am coding something) 
Yeatte
Thanks again :D
arccos is just the same as inverse cos
it may sometimes be in the program as just acos
It is ^^
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My question is regarding the standard topology on R, I was to prove that any given interval is connected(and then that no other subsets of R are connected, but that implication is somewhat straightforward)
thing is, I wanted to outline my idea of a proof so someone can check whether it is right:
given an arbitrary interval J, we assume it is not connected, then, we can find a continuous surjection f:J->{-1,1}, since f is surjective, there exist some a,b such that f(a)=-1 and f(b)=1
then, by the intermediate value theorem, we know there must exist some some c ∈ (a,b) such that f(c)=0, however, since we know J is an interval, and a,b∈J, necessarily, c∈J, thus, our given function maps to {-1,0,1}, not {-1,1}, which implies the stated surjection f does not exist, and hence J is connected
sounds reasonable
i can't remember what is used to prove IVT.
just in case there's a circular issue
isn´t IVT a result previous to the definition of the notion of connectedness though?
if it is, then good
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You're missing 5 other solutions
oh
You're better off finding the general solution
and using that to determine all the solutions in the interval
$\sin(a) = \sin(b) \implies a = b + 2k\pi \quad k \in \mathbb{Z}$
.RODATA
$2x = 3x - \pi + 2k\pi \quad k \in \mathbb{Z}$
.RODATA
find multiple solutions in range [0, 2π)
Or $a=\pi -b+2k \pi$
Civil Service Pigeon
x = -2kpi?
so when k = 1 x = -2pi which is extraneous, when k = -1, x = 2pi also extraneous, when k = 0 x = 0
and k can only be integers
so
im confused
.
@granite anvil Has your question been resolved?
@granite anvil Has your question been resolved?
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chat
i have a question
ok so
is it possible to write u = [2,2] as a linear combination of v=[-1,1] and x=[3,-3]
assuming u v and x are vectors
what my teach did was like
2 = c1(-1) + c2(3) and 2=c1(1) + c2(-3)
and basically just added it
right
but why
why did she add the equations
it makes sense visually but i didnt understand that part
once you have a system of linear equations, a common method of solving those equations is adding them together
makes sense yeah
When you add these two, c1 disappears
