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guys can we get back to my problem
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MOOJY
no it's not commands š
Oh sorry lol
yeah
I replied to the wrong person
If you want to test commands and LaTeX, please go to #latex-testing
So that @pliant palm can post his questions
@pliant palm Has your question been resolved?
@pliant palm Has your question been resolved?
@pliant palm ive said all that i have to say rn: you need to relearn exponent laws, cause without those you'll just drown in anything logarithmic
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There is a coefficient on the sin term, I'm not sure how to deal with it, I haven't worked with the Euler's formula in a while
I'm supposed to convert the number to polar form
i mean you can factor out the 10e^(-t/10)
Maybe I should have started with that
so you get 10e^(-t/10) (cos(pi t + pi/4) + j10 sin(pi t + pi/4))
Ye I did that but I don't know how to deal with the 10sin ... afterwards
let's just call the argument of both trig functions x
cos(x) + j10 sin(x)
cos(x) = (e^jx+e^-jx)/2 and sin(x) = (e^jx - e^-jx)/(j2)
this should do the trick?
like work through all that and i think you will end up with something workable
Probably, I'm kind of remembering that, can you link a source for that so I can look it up deeper?
uhhh Wikipedia article for euler's identity i guess
or just look up trigonometry in terms of complex exponentials
This is what I was remembering
I'll have to look it up
i gave you the necessary formulas
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find all natural $n$ such that there exists a prime solution $p,q,r$ to $p^n+q^2=r^2$
skissue.in.a.teacup
considering even odd either:
1.p,q odd r even
2.p,r odd q even
3.q,r odd p even
4.p,q even r even
for 1. since r is even then rhs is 4, but lhs is obviously greater than 4 so no
for 4. 2^n+2^2=2^2 doesent have natural solution n
for 3. then 2^n=r^2-q^2
by zsigmondy since 2|q-r then r^2-q^2 has a prime divisor thats not 2, so impossible
im not too used to using zsig so this could be completely false (please fact check this)
so whats left is p^n=r^2-4=(r-2)(r+2)
thats where im stuck
Theres a solution here so something gone wrong
oh wait n=2 is one of the exceptions to zsig
Over here notice that r-2 and r+2 are powers of p
oh wait yeaa i was thinking of that but i thought it didnt have to be as r-2 and r+2 arent powers of primes but i forgot p is prime :p
so r+2=p^m(r-2) => 2(p^m+1)=r(p^m-1)

r=2(p^m+1)/(p^m-1) needs to be an integer, if p^m=3, then r=4 which isnt prime
any other p^m>=5 except 3, (p^m+1)/(p^m-1)=1+2/(p^m-1), for any p^m>=5 then 3/2>=1+2/(p^m-1)>1, for twice this to be an integer would need to be in the form of a/2 for some integer a, and with the bounds the only possibility is a=3 => p^m=5 => p=5, m=1 => r=3 (prime)
thus (n,p,q,r)=(1,5,2,3) is a solution
so the only case left is 2^n=r^2-q^2
id reckon we can do something simmilar
Yeah powers of 2
2^n=(r-q)(r+q)
r+q=2^m(r-q)
q(2^m+1)=r(2^m-1)
r/q=(2^m+1)/(2^m-1)
since gcd(2^m+1,2^m-1)=gcd(2,2^m-1)=gcd(2,-1)=gcd(2,1)=1, then (2^m+1)/(2^m-1) is unsimilifiable, since by checking we can see that r=/=q then that must imply that
2^m+1=r
2^m-1=q
uhhhhhhh
Maybe start with r-q=2^a
r+q=2^b
solve for r, q in terms of a, b
r=(2^a+2^b)/2=2^(a-1)+2^(b-1)
q=(2^b-2^a)/2=2^(b-1)-2^(a-1)
since a<b and r is odd then a=2+2^(b-1)
q=2^(b-1)-1
uhh am i srupid or does this go back
actually i feel like ive done something lime this but the base being 5 instead of 2, lemme try and find it
ok nvm i guess not
Probably a slightly easier way to use
But now you see q is one less than a power of 2 and r is one more than a power of 2
Theres some factorisations you can use to find more information about b
if m is even, then qā”2^m-1ā”0 mod 3 => q=3k, since q is prime then k=1 so q=3, thus m=2 so r=5, which holds thus (4,2,5,3) is a solution
if m is odd then rā”2^m+1ā”0 mod 3 => r=3l, since r is prime then l=1 so r=3 and m=1 and q=1, but 1 isnt prime so no solution
so 1 and 4?
Yeah looks fine
ok tyy
I just considered that 2^a+1 prime implies a=0 or is a power of 2
wait what
Yeah because if a has an odd factor c then 2^(a/c)+1 divides 2^a+1
But yeah not needed, too complicated
Just doing the fermat/merscenne prime stuff
@rough talon Has your question been resolved?
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ok tyy
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\documentclass[12pt]{article}
\usepackage{amsmath, amssymb}
\usepackage{geometry}
\geometry{margin=1in}
\title{Task (d): Geometric Action of Linear Transformations}
\author{}
\date{}
\begin{document}
\maketitle
\textbf{Question:} Let ( n \in \mathbb{R}^{2 \times 2} ) be an invertible matrix with ( |\det(n)| = 1 ). Describe geometrically how such matrices act on vectors in ( \mathbb{R}^2 ), and explain why their inverses represent exact reciprocal transformations.
\bigskip
\textbf{Proof:} Since ( n ) is invertible and ( |\det(n)| = 1 ), the linear transformation ( T_n(\vec{v}) = n\vec{v} ) preserves area in ( \mathbb{R}^2 ). It may rotate, reflect, or shear vectors, but does not compress or expand space. Such transformations bend or redirect slopes smoothly without distortion.
The inverse ( n^{-1} ) satisfies ( T_{n^{-1}}(T_n(\vec{v})) = n^{-1}(n\vec{v}) = \vec{v} ). Thus, ( T_{n^{-1}} ) exactly undoes the action of ( T_n ). If ( T_n ) rotates by ( \theta ), ( T_{n^{-1}} ) rotates by ( -\theta ); if it reflects or shears, the inverse performs the reverse. Both preserve area due to the determinant condition.
\textbf{Conclusion:} Matrices with ( |\det(n)| = 1 ) bend space without distortion, and their inverses reverse this action precisely. Together, they form reciprocal transformations that preserve both area and structure in ( \mathbb{R}^2 ).
\end{document}
Asian Math Nerd
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Helllppo
hello
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maje a new help channel
who uses n as a name for a matrix
its in the question
Welcome to mathcord
well whoever wrote the question still made the decision to use n for a matrix
so my question still stands
Free will
as long as you know what n stands for
The person to write the question realized they has free will
exactly
is it good though
just because you have free will does not mean that you should use bad notation
calm down now
Why not?
well I wouldnt call it a proof but its a description of whats going on, sure
If I had free will
I would do anything I wanted
probably good enough for whatever you need it for
\documentclass[12pt]{article}
\usepackage{amsmath, amssymb}
\usepackage{geometry}
\geometry{margin=1in}
\title{Advanced Task: Geometric Action and Eigenstructure of Invertible Area-Preserving Maps}
\author{}
\date{}
\begin{document}
\maketitle
\textbf{Question:} Let ( n \in \mathbb{R}^{2 \times 2} ) be invertible with ( |\det(n)| = 1 ). Analyze how such matrices affect orientation and structure in ( \mathbb{R}^2 ), and explain how their eigenvectors and inverses reflect this action.
\bigskip
\textbf{Proof:} The matrix ( n ) defines a linear map ( T_n(\vec{v}) = n\vec{v} ). Since ( |\det(n)| = 1 ), the transformation preserves area. If ( \det(n) = +1 ), orientation is preserved; if ( \det(n) = -1 ), orientation is reversed. The map may rotate, reflect, or shear vectors, but it does not alter global scale.
If ( n ) is diagonalizable, then it has real eigenvectors ( \vec{v}_1, \vec{v}_2 ) such that ( n\vec{v}_i = \lambda_i \vec{v}_i ). These vectors span invariant lines under the transformation. Since ( \det(n) = \lambda_1 \lambda_2 = \pm 1 ), the eigenvalues are constrained to lie reciprocally across the unit circle in ( \mathbb{R} ) or ( \mathbb{C} ).
The inverse ( n^{-1} ) satisfies ( n^{-1}n = I ), and geometrically undoes any rotation, reflection, or shear applied by ( n ). If ( \lambda ) is an eigenvalue of ( n ), then ( \lambda^{-1} ) is an eigenvalue of ( n^{-1} ) with the same eigenvector.
\textbf{Conclusion:} Matrices with ( |\det(n)| = 1 ) are structure- and area-preserving maps. Their eigenvectors mark stable geometric directions, and their inverses exactly reverse deformation, maintaining reciprocal behavior in slope, scale, and orientation.
\end{document}
Asian Math Nerd
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can you check this one as well
the eigenvalues do not have to be on the unit circle
This again?
It was posted by another guy with a clear GPT formulated text
that explains it
it is the 3rd time I see it
about the same kind of random more or less correct writing I would expect from gpt
last time it talked about |det(n)| defining a norm on the field of matrices
they're doing better with prompts
\textbf{Question:}
Let ( A, B \in \mathrm{GL}_2(\mathbb{R}) ) be invertible ( 2 \times 2 ) real matrices such that ( \det A = \det B = 1 ), i.e., both are area-preserving linear maps of ( \mathbb{R}^2 ). Suppose ( AB = BA ), meaning the two transformations commute. Prove that if ( A \neq \lambda I ) for any scalar ( \lambda \in \mathbb{R} ), then ( A ) and ( B ) share a common eigenbasis over ( \mathbb{R} ) or ( \mathbb{C} ). That is, there exists a basis of ( \mathbb{C}^2 ) (or ( \mathbb{R}^2 ), if possible) in which both matrices are simultaneously diagonal or triangular.
Geometrically, this means that if two area-preserving linear transformations commute and one of them is nontrivial (not a scalar multiple of the identity), then their actions are aligned along shared invariant directionsārotations about the same angle, shears along common axes, or dilations along reciprocal eigenspaces. This question probes the deep relationship between symmetry, structure, and the algebraic constraints imposed by commuting volume-preserving linear operators.
Asian Math Nerd
\textbf{Proof:}
Let ( A \in \mathrm{GL}_2(\mathbb{R}) ) with ( \det A = 1 ) and ( A \neq \lambda I ). The characteristic polynomial is ( \chi_A(x) = x^2 - \operatorname{tr}(A)x + 1 ). Since ( A \in \mathrm{GL}_2(\mathbb{R}) ), it has two (possibly complex) eigenvalues ( \lambda_1, \lambda_2 ) satisfying ( \lambda_1 \lambda_2 = 1 ). Consider two cases.
\emph{Case 1: ( A ) is diagonalizable over ( \mathbb{R} ).} Then ( A = PDP^{-1} ) for some diagonal ( D ), and the commutation ( AB = BA ) implies ( D(P^{-1}BP) = (P^{-1}BP)D ). Since diagonal matrices commute only with other diagonal or block-triangular matrices, ( P^{-1}BP ) must preserve the eigenspaces of ( D ), i.e., it is diagonal or triangular. So ( A ) and ( B ) are simultaneously triangularizable and share a common eigenbasis.
\emph{Case 2: ( A ) has complex eigenvalues.} Then ( A \sim R(\theta) ), a rotation matrix. The set of matrices commuting with ( R(\theta) ) is the centralizer of ( R(\theta) ), which consists of all matrices representing linear combinations of rotation and scaling in the same direction. So ( B ) must also preserve the complex eigenspaces of ( A ). Hence, ( A ) and ( B ) are simultaneously diagonalizable over ( \mathbb{C} ).
Thus, ( A ) and ( B ) always share a common eigenbasis in ( \mathbb{R}^2 ) or ( \mathbb{C}^2 ).
Asian Math Nerd
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hey guys
did I do something wrong
Why did you conclude the limit to be undefined?
h/h?
because the x are getting canceled out and I canāt get rid of h
Q8) a
you have h/h, what does that evaluate to?
- You can get rid of the h
- Even if you couldnāt, that doesnāt make the limit undefined (e.g., is the limit of h as h -> 0 undefined?)
0
why?
yeah it cant be possible because the denominator must not equal to 0
What's 3/3? And 5/5?
but they defined it as a limit, so the denominator and the numerator are equal in this sense
1
Then what's h/h?
bro those fractions are 1 whole
But this is a limit, we simplify all of the algebra before we apply the actual limit
it is 1 whole but if i sub h in?
^
We are taking a limit, remember
is my working out correct tho?
No, because that limit is not undefined
Up until the undefined part, yes
So close
What is x/x?
Well, the limit will approach 1 regardless
What is $\frac{0.000001}{0.000001}$, for example?
;(
So your limit is approaching one, but the function is not necessarily defined at zero
That is where your confusion is
,w plot x/x
Looking qualitatively, the fraction h/h will approach 1 from the left and the right but it will not be defined at h = 0
I meant 1 my bad
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How do I make these two equations equal? (more explanation pending just claiming this channel before someone else does)
I was trying to use this equation to replace the top part
replacing 1 with a, and x with... oh that should be b
the bottom integral diverges
new one, still has issues though
how do I undiverge this integral? I havent learned this stuff in maths yet so I'm kinda oblivious
well the integral measures the area under the curve. and in this case there is infinite area so the whole integral doesn't have a value except maybe infinity
there is a way to assign values to divergent integrals called the cauchy principal value although desmos will not have a function for that
Why? What are you even doing it for?
just overcomplicating the a/b/beca equation
make it integral of a/sqrtb instead
idk what that means
MathIsAlwaysRight
is this good enough?
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@warped heart isomorphism = epimorphism and monomorphism
Please don't ping me unsollicited; otherwise, yes
srry I saw you typing, my bad
Isomorphism <=> det(f) nonzero
(Because it's a square matrix)
So it's (again) the same method as all the exercises you did so far!
Except this time in the condition defining S you also have the same value a that appears in the matrix for f
this follows from rank nully?
This follows from the fact that if dim(V)=dim(W) and f:V->W is linear, then f iso <=> f mono <=> f epi
but we want NOT an isomorphism
But in fact, it should be a result in your notes that f iso <=> det(f) nonzero
Yes, so what do you need then?
which means either the det is zero or Im(f) = codomain(f)
is possible that if f is not an isomorphism, then f is epimorphism or f is monomorphism or f is neither
Re-read this part
In fact, if f is mono, then it is also epi
So if f is not mono, it is not epi
Next, the condition that f(10,1,13) be in S means that f(10,1,13) is a vector that satisfies the condition x1-ax2=0, which gives you a second equation in a
right
I suspect both will be quadratic equations in a, and only one solution in common so perhaps only one value for a in the end
You'll have to do the computations to know for sure 
So your first job is to compute det(f) and solve the equation det(f)=0
Then, to inspect the second condition, you have to express (10,1,13) in the basis B
To compute its image under f
if f is not epi, then its not mono aswell
but since f is NOT a isomorphism, is possible that f is NOT mono and f is NOT epi
ok so only possibility for f for it to be not an isomorphism is when its not mono and not epi, otherwise we get a contradiction
Yeah
ok and if its not mono its not epi, because rank nullity, let me find det(f)=0, the not mono condition
Yeah, the determinant is easy to compute here
first row cofactors expansion
So that gives you the only two options for f to not be an isomorphism: either a=-3 or a=2
There is one last condition to check though
but f(x) ā S
how do I write that in the equation
ok
@cobalt crow Has your question been resolved?
do you see the mistake @warped heart srry for the ping
I will double check If i found the coordinates of (1,1,13) in basis B correctly
but something feels off
,w det {{1,0,0},{1,a,3},{-1,2,a+1}} = 0
,w {{1,0,0},{1,2,3},{-1,2,3}}*{{9},{1},{-3}}
I appreciate it matplot ā¤ļø š
.solved
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can someone explain how to do this cos inverse (x^2 -11)
if anyone can explain using the number lines that would be easier too
You've done it correctly till the number line part
The union part for the first case is correct too
For the second case you need to see where the negative sign is
@pseudo python
second case?
ohh okay also i think in the first one won't it be like ] instead of ) next to the 10 values
Oh yeah lol
Yeah now do this
for second case ?
ohh wait
?
so how do i get the overall domain
Intersection or union?
intersection
Correct
ok wait i try and then ask u
Indeed
is it correct?
Yes
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can someone explain this step
,w simplify (x + sqrt(10)) * (sqrt(7 + 2x) + sqrt(5) + sqrt(2))
Just substitute x = sqrt(10) and then simplify
Civil Service Pigeon
ohh
ok this was the part i had a doubt in
thx
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I have found the parametrization for X, x(t,s) = (st,st^2,st^3) but I don't know how to find an equation for the closure and show it's exactly X
@abstract iron Has your question been resolved?
<@&286206848099549185>
we can definetly cut h
the derivative is defined in such a manner tbh
This should be correct, lemme check b) and c)
@abstract iron Has your question been resolved?
Not used to writing in Englisch, I hope itās fine
getting some food now, solving c and d later
alright thanks!
!nosolution
I forgot the command, you're supposed to guide through, not just solve
As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.
Sorry my first answer ever
Umm ok so do u understand b?
And what do you have on c so far?
@abstract iron what do you have on c so far and do you have any questions about b?
So the closure is the border right, like when 2x = y squared
Yup
Havenāt you talked about a way to calculate closures in school yet in general? (If this is homework)
We have but I kinda forgot about it
Prolly read through you notes once again?
āYou canāt draw a tree without knowing what a tree is ā
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f1x = ccw
f1y = cw
f2x = ccw
f2y = cw
f3x = ccw
f3y = cw
f4x = ccw
f4y = ???
can somebody confirm the x/y rotations from Point A for each force shown
@halcyon lintel Has your question been resolved?
Well
CCW means counterclockwise rotation and CW clockwise rotation, right?
The force that passes through the point does not cause rotation because it acts on the zero arm, you did not take that into account
I mean the forces components
@halcyon lintel
hey sup
yea
cw =clockwise
ccw = counterclockwise
Great
Do you understand this line?
no
are you tlaking about force 1?
the one on the very left?
or which force you we talking about here?
Besides, what exactly is the question - to determine the rotations of these forces (their components) with respect to point A, right?
!xy
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.
Yes, for example
i just want to know the direction of fx and fy components in respect to point A, cause if I can figure this out, I know how to solve the rest
but i keep getting screwed with the directions
direction in respect to a??
ye
or direction in which they rotate about a??
f is the resultant force?
These are two different things.
does it matter which force it is cause it doesnt say
it just shows F as shown in the visual
What are fx and fy?
What even is your axes convention
what do you mean what is fx and fy? you want actual numbers?
We want your axes convention.
I think he means this since he used CCW/CW to describe the rotation
Prolly
all i want to know is the rotation of the fx and fy components in resepect to point A
that's it
...
whether its clockwise or counter clockwise
Ricky read my message
Oh, it dawned on me
what do you mean by that?
What is x and what is y for you
By fx and fy he means the components of each force
x is the horizontal?
the standard x (horizotal) y vertical axis
im aware
yeah ok then your x is the horizontal
why would x be the vertical?
now can you explain why you think f1x rotates about A at all?
that's what im askiing...it looks as if f1x is completely on the x-axis of point A
it can be anything, it's up to you to define it. If we had worked with a different axes convention than yours we would have had to redo the whole thing.
Indeed
Yeah, and what does that mean?
0
Wdym 0
So the moment of force is 0?
Correct
Now can u apply the same for fy
Keep the formula in mind btw
yea but the force isn't pointing 180deg. you can see it's pointing upwards to the left
so there must be some fx rotation
$MOF = Force * r_{perpendicular}$
Executor (ask on server b4 DM)
We just determined that it passes through the perpendicular line
Which means $r_{perpendicular}=0$
Executor (ask on server b4 DM)
so if there's no rotation, is the fx value positive or negative?
im guessing positive then right?
Fx is the force, MOFx is the moment of force by Fx
Which one do you want, make it clear
you're kinda confusing me even more
it depends on the adopted system, but in general it is negative (assuming a regular Cartesian system)
If you're finding MOF1x then there's no reason for us to care about F1X here
since $r_{perpendicular}=0$
Executor (ask on server b4 DM)
yea it's just the standard cartresian system otherwise i wouldve stated which system i was using
Then it's negative since it acts to the left
thta's what i was thinking
But according to your question it doesn't matter
so f1x = its negative so doesnt that also mean it would rotate cw?
As already said
since cw = negative?
Nope
Re-read the previous messages
i dont know even know which message you're referring to
its ok...i
hopefully others will chime in
You wrote yourself that there is no moment from this component
Since the arm in respect to point A is zero
yea but didnt you also say the value was negative since the fx is pointing left?
Just because a force component has a value, it does not mean that it causes a moment
The moment is defined with respect to a point or axis (here with respect to a point), if we took another point it could exert a moment
If the arm weren't zero
can i show you a different example?
Yeah, sure
k one sec
Look here, it passes through A => the moment from this component in respect to point A is zero
Want to find out for yourself, it's simple, imagine towing a car, does the towed car rotate while driving?
,rccw
Exactly
f2x = no rotation?
For f2x there is a rotation (according to the drawing)
if you took fx from the bottom though
wouldnt the force be going directly to the left on the x-axis of point a?
This doesn't matter, according to the axiom of mechanics a force can be moved along its line of action without changing the external effect it has on a rigid body
This means that the total moment about point A won't change anyway
ok so back to this example
becaues for forceX is pointing AWAY from point A...fx would cause no rotation
becaues regardless which FX you choose, top or bottom, it makes no difference
is that correct?
for Force2X, there would be CW rotation becaues it'spulling to the right about point A?
Force2Y = no rotation becaues it's pulling AWAY from point A?
This is true, but the question is why complicate things, besides you would have to determine the position of the force attachment point (and there are no grids in the upper position as you can see)
I agree
I agree x2
but dont you calculate the distance from the tail part of the force?
so for force 1
You calculate the arm of the force from the point of application of the force
One grid is 2?
it should actually be 30
for f1y
cause the force is 30 (hypotenuse)
so if we scale up the height and width, y would be 30
It should be 34 * sin(15/17)
is that correct?
to get the moment of f1y?
if pictured the force as a triangle......h=15, w=8......we use py.theorem to find hypotenuse
so that would be 17
but the force is 34
I didn't get it, why do we have to scale that? First of all, these 15 and 8 are the dimensions of this force, right?
Yea
um
we scaled up the y and x so we can calculate the moment forces
or else the 15 and 8 dimensions wouldn't be scaled correctly with the 34N force
like a triangle that has
width=8
height=15
should have a hypotenuse of 34N
if 15 and 8 are the dimensions on which the force acts (i.e. in units of length), then you are wrong
so we use py.theorm with height and width which equals to 17 which gives us the hypotenuse
so now the triangle has
w=8
h=15
h=17
which?
its just the ratio or angle
like if you wanted to make a triangle out of the 34N force
34N would be the hypotenuse
so you just do arctangent
arctangent(15/8)
which is 61.9
but i dont need to figure out the angle right now cause i already know the FX and FY
Just multiply the forces by 1/2 and it makes sense, just dont forget to scale it back up when youre done with math. I assume one unit length in this case is 2N which is confusing
it just needs to be scaled up so that the width and height is equal to 34N (aka the hypotenuse
im the one that actually needs help lol
I understand your concept, and it's perfectly understandable, but yeah with such assumptions it makes sense
there's not really any assumptions
but anyway, this is beyond my original question....
Okay, let's proceed
not sure if even still understand the whole direction thing since we got so off topic
With the moments
Just confirming whether f4x is cw or ccw right?
i need to undestand the direction for fx and fy for all four forces
i keep getting them mixed up which messes up my final answer
So for f2 I agree completely
f2x - there is a moment CW
f2y - no moment
wait
Let's continue
dont give me answers for f3 f4
Ok
f3x = negative rotation....
because
like you mentioned earlier, if you take the top fx, it would rotate around point A ccw
correct?
wait
wait
its below point A
so its CW
or negative value
f3x = negative
f3y = no rotation
You mean CW?
Depends which side of the point its on iirc
why? can cw mean positive in other contexts?
nevermind. lets just forget it.
ok f4
you can take any form you want for equations, the important thing is to stick to one convention
you will simply get opposite signs (as if you multiplied the equations by minus 1)
f4x = neg/cw
f4y = neg/cw
the first force messed me up
so because the force is pointing AWAY from the pivot A
FX will have 0 rotation
but if F1x was pointing the exact way but downwards, then Fx would be cw/neg right?
cause then the top f1x would be rotating cw around point A
I recommend you to draw the components of the force, it will be easier for you then
I have no idea how to approach f3, is it external force? Its not in the grid
And you were right before, f1x is 16 and f1y is 30, I got a brain lag š„²
I plugged sin(15/17) instead of just 15/17...
But nvm
I think to visualise it better we can consider F3 as a free vector here, and displace it forward (to the left side)
this is just for understanding purposes btw
it is perfectly fine to solve f3 as it is
Yeah fair, im just used to the scalar moment equation
Just need to use F* r_perp
Yes, they seem correct
this was another question i was given.....i think i was able to solve it as long as my directions are correct
fx = cw
fy = ccw
are my directions correct?
About which point
D
The thing is in mechanics there is an axiom which says that without disturbing the equilibrium of a rigid body, we can move the point of application of a force anywhere along its line of action
Yes they are correct
? Is that a thing??
Hm
was that to my question?
yes
cool...thanks
Ok now that i think about it it does seem like a thing
Which is why this would work 
Let a force P act on a rigid body, applied at point B. At point A, a zero pair is added ā consisting of two equal and opposite forces: P1 and -P1. As a result, the system now consists of three forces: P, P1, and -P1. Next, a second zero pair is subtracted from the system ā consisting of the original force P (at point B) and the force -P1 (at point A).
In the end, only the force P1 remains.
This is why basically
thanks everyone for your help...i'll leave this chat open so you guys can continue your discussion
Alrighty, i gotta go now if you guys dont have anything else to say @trail patrol @remote current should i close
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how do i graph 23:36 on https://www.youtube.com/watch?v=x32Zq-XvID4
This deceptively simple math problem has stumped mathematicians for almost 300 years! š Head to https://hensonshaving.com/veritasium and enter code 'Veritasium' for 100 free blades with the purchase of a razor. Make sure to add both the razor and the blades to your cart for the code to take effect.
If youāre looking for a molecular modelli...
wdym by "how do i graph"
like how to make a graph like that?
yeah
how do i make a circle graph that moves like that
on desmos
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why doesnt this work?
as x tends to 0, where does 1/3x tend to?
dne?
so do u understand why we cant write 0
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So i have a question, if x > -1 and x < 1, isnt there a decimals that fit both inequialities?
well in the question it stated that x<-1 and x>-1, not the other way around
both inequalities involve -1 not 1
wait sorry typo
you mean x > -1 and x < -1
the number in both is -1
and there is no such thing as a number that's both above and below -1 at the same time!
i dont get it
do you think there's some number that fits both
x > -1
AND
x < -1
at the same time?
yes or no
When x is > -1 i have drawen the line there, and when x < -1 i have draven the second line there, if we connect them we get some space between
what does this mean?
What is that
and you didn't answer my yes/no question
i dont know, so i didnt answer because of that
When x is > -1 i have drawen the line there, and when x < -1 i have draven the second line there, if we connect them we get some space between
those are two different points though
let me repeat myself:
it is impossible for x to be both left of -1 and right of -1 simultaneously!
ok, i dont get it but ig its enough to know that this is the case then.
what's there not to get
like...
it is impossible for x to be both left of -1 and right of -1 simultaneously!
which part of this is unclear?
well my example i draw, its making me confused
you're confusing yourself
you're confusing yourself with it for sure
What is that curve supposed to mean
can you simply read my statement WITHOUT looking at your own confusing drawing?
When x is > -1 i have drawen the line there, and when x < -1 i have draven the second line there, if we connect them we get some space between
Ok, and that space ur talking about does not meet the conditions we need
Any point in that space
Will either be greater than, equal to, or less than -1
It cannot be any two of these three things at once
i said this exact same thing twice before but somehow it was not clear
Kek i didnt read sorry
You didnt talk about the space between the points.
but anyway
thanks
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How do I find AI and BI if <ABE = <CBD, and AB=6cm
Without using cos(60)*AB=AI
just turn it into an equilateral triangle
I don't know if its an equilateral triangle
reflect triangle ABI along the line AI
this setup looks sus
ye idk what is this trying to do
What would I do next?
it looks like an isosceles triangle
but there are two angles equal to 60
Oh yeah equilateral
<BAE = <CAD
under these conditions E and O would be the same point
Oh I made a typo there
wait nvm
what the hell is E tho
oh you made a typo
in the original statment, E would have had to been the centre, from congruence/perp bisector theorem
question is fixed now
can you show the original question
why are you trying to do this without trig
I just realized that I misread the problem
I figured it out now
thanks for the help
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hiiiii i need help i have a maths test tommorrow and im really scared
Should then go ahead and study
If your goal is to do good
And come back here with any questions on what you dont understand
I just have to pass
im really horrible at maths i have adhd and i just cannot do maths in general
i have a lot of formulas what do i do and how to approach them?
Study the book
Fully
Dont just look at the highlighted stuff or whatever
You got a full day do 1 full reading
Of all the theory
thing is all i struggle with is the exam questions neverrrrr are the way book exercises are presented
Then come here every time you get stuck understanding and ask
I don't have a full day only 1 night š¤£
Dont go on exercises
First read 1 time the theory
In order
do not ask during the exam tho
theories wont help because the tests are from exercises :c
If you dont understand something come ask
what if I do š
Bro
What kind of logic is that
Make it make sense
ok but genuinely if i could I'd just use chatgpt
You ask before a test question to better understand theory so you can apply it
šØ

I am a psychology student I DO NOT NEED MATHS
If you dont understand theory you cant use it most of the time
rlly???!
Yep
If we catch on u definitely will get banned
And we usually can
And questions probably boosts progress by a crazy amount
damn bro š
yeah test cheating is a bannable offense on here no exceptions
thought u guys r chill lol
alr alr
but genuinely if they were gonna cheat
and had their phones with them
just use gpt man
I mean up to you what you do
nah i have to study phones arent allowed.. š
Nah we're extremely unchill
Giant sticks up our butts fr
smoking za while i do maths šÆ

LMAOOOOOOOO
How is there no auto ban
LMAOOAO stop as a kanye fan thats FUNNY
It did prolly
Just practice the problems a lot
there's a movie on japanese exam cheating technology tho...
Math is not something you can learn over night
Damn delay crazy
To learn math, you must practice
thank god im serbian š¤£
BRO I HAVE TOOOOOOOO PASSSSSS
iz cega imas kontrolni majke ti
JUST PASS..
OMGGGGGGGGGGG
ur serb??? š
yeah
Need some assistance with these 2 polynomial function graphs
This is my progress, any thoughts?
when is the test due?
how much time is left to finish your test
Itās not a test just self practice
Iām serious
Parents want me to study to take calculus next year so I am practicing to take a credit by exam
So this is self taught and I have been using YouTube videos for most things until I got confused with this
so why does it tell you to print it out and submit it for grading
(16 points)
in ninth grade they made me do the same shit
It is a pdf of a quiz?
good luck bro
But itās not for a grade because I am doing it for practice
šš»
!occupied
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this is @sinful belfry's help channel even though the name doesn't show up
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use gpt lol people here won't help
wow he got banned?
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so, i gotta find all z in C (C for set of complex numbers) such that.
What i tried is, let z = a + bi -> z = |z|(cos x + sin x) = |z|e^(xi)
then z^5 = ((|z|)^5)e^(5xi) then 3(z^5) + 2(|z|)^5 + 32 = 0 -> 3(((|z|)^5)e^(5xi)) + 2(|z|)^5 + 32 = 0 but since 2(|z|)^5 is a real and has no imaginary part, then 2(|z|)^5 + 32 is also real and has no imaginary part, but this is only possible if 3(((|z|)^5)e^(5xi)) also has no imaginary part which implies e^(5xi) = 1 which is only possible if 5x = pi + 2kpi for some integer k, then e^(5xi) = 1 and 3(((|z|)^5)e^(5xi)) + 2(|z|)^5 + 32 = 0 -> 3(|z|)^5) + 2(|z|)^5 + 32 = 0 -> 5(|z|)^5) + 32 = 0 -> (|z|)^5) = -32/5
is the way i'm solving this right?
e^(5xi) = 1
what are you doing here
can it be any other value? i need 3(((|z|)^5)e^(5xi)) to be -2(|z|)^5 - 32 which is real and has no imaginary part
that implies 5x = pi + 2(pi)k for some integer k, right?
or just Ļk
oh, wait, can also be e^(5xi) = -1
hmm, thanks for the correction, let me keep attacking the problem
@restive crest Has your question been resolved?
i don't understand well why i have to consider both k even and odd for 5x = pi + 2(pi)k, can't i just say x = (pi + 2(pi)k)/5 for any 0 <= k < 5?
k being an integer/natural of course
for k even, we have
5r^5 = -32
we want solutions with r>0
since we took it to be the modulus
hmm, let me re-read the material, i don't understand 100% this
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HI UYS
,w 1+1
something like that
no problem
$1 + 1 \equiv 0 \pmod 2$ actually
haseeb

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Could someone help me figure out what I'm doing wrong? The assignment specifically asks for induction, and a,h are positive reals
,rccw
@winter crater you messed up the inequality
Where?
In the case of k+1?
I see, thank you. I'll take another crack myself in the morning š¤¦
Well, technically also the second one doesn't need one. Because it's a^1 but that's probably what messed you up
Yeah, I think I was looking at that a instead of the one in the statement
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How Do I do part ii)
Yea
how do I do it without coz the test aint give me one
also, do I use x = 9 or x = 8.5
but how can I find all those given that n is not found
They go on to form a quadratic from this
i understand mu and sigma, but how did they -0.4. Also for normal approx, shouldnt we use continuity correction
@wraith heart do you calculoate z score from calculator stat function or smthn
<@&286206848099549185>
@magic sentinel Has your question been resolved?
do u know how to use a standard normal table?
In statistics, a standard normal table, also called the unit normal table or Z table, is a mathematical table for the values of Φ, the cumulative distribution function of the normal distribution. It is used to find the probability that a statistic is observed below, above, or between values on the standard normal distribution, and by extension...
ik how to read one
but i wouldnt have access to one during an exam
How did they calculate the z score
to be -4
without on
which calculator
I'll start from the beignning
Can someone explain how they got -0.4 as the z score
You will be given a chart or calc on your exam
if they didnt have table
Or, they'll give you a few values you need
In this exam there wasnt a chart
unless they got on the day itself
<@&268886789983436800>
My second question is
Why did they not use continuity correction
If its normal approximation
Should it be 8.5 instead of 9
yea i think
umm
why did they not use?
not using continuity correction can be excused due to the specification
of a LARGE sample space
can i simplify root 0.09 n to 0.3 root n
LARGE pool of people, the ±0.5 can be excused (hoeever i do agree it sjouldve been used)
ahhh sure excused
makes the algebra cleaner
i dont see why not
as for the z score i once again ask you what calculator you have
but tbh inferring from the fact that it's given to 4dp it's highly highly likely a table was given
it was not given in the paper
i assume that that the teachers handed it out not part of the paper
hence not shown
without table , you have to calculate this yourself
$P(Z \le z)=\int_{-\infty}^{z} \frac{1}{\sqrt{2\pi}}e^{-\frac{x^2}{2}}dx$
ćøćć»ć¼
tables are usually given out in extra material
like formula sheets
the question sheet will usually just contain.... questions
in our syllabus, usually given out as part of question
like a small relevant portion of the table
hmm well is the above integral in your syllabus
im assuming the students did use it but not like within the test paper of formula sheet
i dont think so
our teachers say its a long and complex formula
so i assume its not taught
anyway most likeley they used formula sheet
I got n = 97 with continuity correction
thanks guys
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can someone teachme how to solve this ?
so the boats have rectangular cross-sections
this is always something I like to do, just break down the question
sketch them on your diagram. what do they look like?
yumi wake up...

thanks in advance
so breaking down the question:
have you tried sketching the boat on the diagram?
not yet
give it a shot
what does it remind you of?
what is the line that the bottom of the boat makes called (as a part of the circle)?
main question: if waterway is filled with 4.5 ft of water underground, what is the max width the boats can be?
oh nvm
seia is probably smarter than me š
semi circle?
okay im bad this ;-;
uhh
(the corners of that line touch the semicircle. sorry for poor drawing)
i knoiw that but i forgot tyhe name.. QnQ
secant?
it's not a secant
it doesn't extend past the semicircle
calling that a secant implies the boat can puncture the waterway
aye alright, i'll give you the name
this line is called a chord
š„ŗ it went over my head
aye anyway
kinda liek this
yep, correct. but now we don't have the angle. but we do have the radius
yes
