#help-49
1 messages · Page 148 of 1
It is
so if i didnt use cosine law i would use vector for this question?
Yeah
There's many ways to peel an apple
We are only concerned with the form or expression
It doesn't matter since the question doesn't ask you to find the resultant
But you could use it since it gives the same form
Find the resultant force acting on the object
Force is a vector
Since acceleration is a vector
yes
wait but
do u solve that question?
like what do i do with it
a-b?
This
Understand it intuitively.. You are applying force upwards and sideways
thats for paralellogram
just ask your teacher to help
its like a class tutor
i dont think its possible to understand vector addition at first so easily
idk what their contact is
whenever u meet
Fr watch videos online
like what would i write
is it just 2N
i draw a middle line between them and state 2N?
Do you know trig
ye
Well then you can solve it
Yup
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with vectors if u have 2 that are perpendicular to each other
wait ima draw
will the answer for these be the same
even though like one of the arrors is following the other
question says find the resultant vector for the following
idk
i wana know if they have the same answer
cuz for the right u can use trig to solve it
oh, resultant vector
yes
the vectors arent the same, but the modulus are the same
it says to find the resultant vector so surely you have to know the direction and length
doesnt it give the direction and length
oh ye i forgot to add N to it
but thats just like outward
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.
rip
ok but the original
is
thats what it gives
and the question is find the resultant vector for the following
oh
yeah, first you draw the resultant vector to show the direction
then you find its length
so the green
is the resultant vector right
and for length
uh
is it just 10-10
how do we do it
what
wait how do u do it
think of it like a very normal geometry problem without the vector
oh ok so its just pyth
ye
i thought it would be hard bruh
what does this mean then
wait i cant take pic so lemme draw
eg a-b= a + (-b)
turns into
which then turns into this
i was tryna draw dotted lines
well, yeah, that's true, a+b = a+(-b)
in this formula, the length doesn't always satisfy that
oh so thats a seperate formula?
the length can be found by treating it like a normal geometry problem
yes
that formula is only to determine the direction of resultant vector
oh the direction
so my final answer would be just draw that middle line
with it labeled as 14.14
,w 10sqrt(2)
yep that's right
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Relation between statndard deviation and mean deviation?
My book says
5× mean deviation = 4 standard deviation
Idk, did you try googling it?
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I'm kinding of having a hard time working out what's gonna happen with the 7 A current source in between
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H
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how do i prove T(n)=Theta(n)?
also how do i solve when 9=a,13=b,18=c , and i a,b,c are different
as in different numbers from above
Is t(n) a sequence??
Or arbitrary function
RR
@spice scroll Has your question been resolved?
Bruh wth-
That rr makes no sense for n=1
Should be $T(18n) = T(2n) + T(13n) + \Theta(18n)$
rak³en
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Is my math correct? I feel like I didn’t do anything wrong
Perhaps it was my algebra when cancelling out the sec^2x
It was in that, it was in my algebra I messed up
I’ll just wait for somebody to confirm I fucked up my algebra lol
Yea I figured it out
Wrong identity
And I should’ve distributed
Yea
Thank you😂
Yea, in this specific problem I don’t think I’ll need to convert back into x
😭
you do because it's an indefinite integral
Oh ok thank you
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✅
The stuff above the bot is my question
Lemme use a better picture so you aren’t craning your head actually
$$sec^2 (x) = tan^2 (x) + 1$$
StrangeQuarkAL
your theta sub is wrong
Your root is √(576+576tan²) but substituting tan does make 576 magically appear
😢
no like
You have your integral right
and you have x=tan(theta)
If you substitute you get √(576+tan²)
Not √(576+576tan²)
yes

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But is a set X said minimal if there is only 1 element in it that satisfies a certain property?
@steady trail Has your question been resolved?
@steady trail Has your question been resolved?
generally a set is called minimal with respect to some property if no proper subset of it also satisfies that property
so if a set with one element satisfies some property then its likely that its minimal, cause the empty set probably doesnt satisfy the property
but it depends highly on the specific property
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Could somebody check my proof? I'm not sure I fully get this whole 'choose-an-epsilon' business, whether it's continuity, limits or even something like this.
(oops used wrong sign in the middle of the second case should be \geq not \leq )
Why is $s^3 - 7 \eps > 2$ should it not be greater or equals?
unrelated but how do you get the filled in box in latex
tobi
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\blacksquare, I think it's in amsmath or amssymb or something
but shouldnt matter I guess
Why so?
Yes, I am not sure that changes the accuracy of the proof.
just choose another epsilon tilde defined as epsilon/2
if thats the problem
usally
Well, that is indeed what I've done (for safety's sake).
But I am not sure why it would be a non-strict inequality anyway
the middle one should be greater than or equal I believe
the s^3 - 7\eps > 2 is right
but s = 3rd root of 2
and that minus a tiny positive number
raised to the third power os smaller than 2
Well, the whole point is to get a contradiction.
Umm... actually, wait.
No, s isn't the third root of 2. I'm saying suppose s is greater than the third root of 2.
ah yeah my bad
Then if I set this inequality to be the case, I'm getting that s - epsilon will actually be an upper bound too.
I think this proof is right, but I only got it after borderline copying a different proof. 😛
it looks good
Excellent, thanks for your assistance... I am never sure with these choose-an-epsilon mind games.
,close
Wrong symbol.
/close
Nope.
use a dot
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Technically this channel is still assigned to me I think for a while so please post in one of the unoccupied ones
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Given that W=240N, what is Q?
Hint: F/sin(theta) is constant for a given object where F is a force acting on the object and theta is the angle that it makes with some fixed line
sine rule?
yeah, but I need help to apply it
Doing the free body diagram of each block. Then, draw the tension forces of the strings.
Like @stiff lion said, an easier and more intuitive method is to draw the free body diagrams and use the fact that the object is in equilibrium so the net force on the object in any direction is 0.
is it ok if B points in different directions in the free body diagrams?
if not, it would be impossible that the forces are in equilibrium
Yes
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So I mean a is clearly false
The mid points are not the same
So let's look at b,c and d
Which of these properties are unique to paralleograms
I think C
I was thinking C was the answer but idk
@iron pagoda Has your question been resolved?
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A delegation of four students is to be selected from a total of 12 students. In how many
ways can the delegation be selected
two particular students refuse to be together and two other particular students wish
to be together only in the delegation ?
for this one it's just 12C4
for the second criteria
in one case, one of the two students is picked, then the other, then neither
@orchid grove Has your question been resolved?
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Are all of these congruent bcs I feel like 1 and 9 are not due to the angles not matching the other angle
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err did i not just post an image here
:/
ok im doing part b
hints are
"you can explicitly find K"
"what has equal power to both circles"
playing around it looks like NK is the diameter of circumcircle ANB, but i have no idea how to prove it
tangents at A and B have something special
yeah its at K but idk how to prove it :(
not sure
its 120?
yea
whar
but yea
call center E, MAE=MAC/2=30
KAB=90-30=60
you uhh dont need to do that
you found angle BAK = 60, similarly ABK is also 60
that makes ABK an equilateral triangle, or AK = BK
and ABK is unique coz AB is fixed
that makes K unique, and it lies on radical axis, which is all lines MN
wait how do you know AK is tangent at A hold on
im retracing my steps and im doing a silly?
MAK = 60 right?
yea but the proof needs AK tangent at A no?
I explicitly draw a tangent at A
I dont construct AK
I draw a line at A, such that it is tangent to the circle
oh phantom point?
i mean like call point K' as a phantom point of tangents A and B, everything above got ABK' to be equilateral, and K' would be proven to lie on the radical axis proving K'=K?
yes
also, not a phantom point, just point of intersection
whats the diffrence?
idk whats phantom point
I am just assuming its something imaginary
while point of intersections is a concrete concept
ok i see
I mean, you just jumped ahead here
I just wanted to show the point of intersection lies on the radical axis coz tangents at A and B are equal in length
cause it seemed useful and it looks true so its worth tryung to prove?
yea, it is. But while solving problems, its not good to find insights based on results
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$Prove that any two consecutive odd numbers are relatively prime (coprime).
$
MY GOD
Hhhhhhhhhhh
Tyt
@somber canopy i recommend first claiming the channel
then type your question
if its long
let n be a prime number
assume n and n+2 are not comprime
so gcd(n, n+2) > 1
since they're odd, it can't be 2
and since their difference is 2, they can't both be divisible by something > 2
Make scenes
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I'm studying a theorem that states a continuous, bijective function from a compact metric space onto another metric space has a continuous inverse. The author provides a counterexample when the domain is not compact, namely f(t)=(cos t,sin t) on [0, 2pi). I wonder, what is the inverse of this function?
it has lots of inverses, because the codomain (x,y) contains points where there doesn't exist a t such that x = cos t and y = sin t.
ok 👍
but you can take a representative, i.e. the unit circle and find an inverse from that
it seems counterintuitive to me that there are lots of inverses when Rudin claims it is 1-1 and onto. Shouldn't this give us a unique inverse?
Rudin is the author, by the way.
It's not injective because f(t) = f(t + 2n pi) for all integer n.
maybe I'm misunderstanding the context
oh, oops. It is injective on [0,2pi)
my bad
I suppose you could define this
$$f^{-1}(x,y) = \begin{cases} \arccos{x} & \qq{if} y \ge 0 \ 2 \pi - \arccos{x} & \qq{if} y < 0 \end{cases}$$
Shuba
But you'd need to restrict the domain of this function to the image of f, which is where x^2 + y^2 = 1
you could equally define g as an inverse also
$$g(x,y) = \begin{cases} \arcsin{y} & \qq{if} x \ge 0 \ 2 \pi - \arcsin{y} & \qq{if} x < 0 \end{cases}$$
Shuba
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hi
hi what is your question
so i was doing
linear programming
so the max value i got was
752 dollars
by putting in 12,38
in the model 12x+16y
however the value is outside the feeasible region
btw i shaded out to see the values better
@stone spear Has your question been resolved?
@stone spear Has your question been resolved?
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sin^2(x) + cos^2(x) = 1 is an identity because x in R
but like tan^2(x) + 1 = sec^2(x) is an identity(?)
technically it isn't right
i mean that begs the question what the equal sign means
it's an identity for all values for which tan(x) and sec(x) is defined
which happens to be the same set
so like we care about the domain?
but i guess there's a problem with that as well
😭
It will work fine until the value u substituting is not undefined
the identity is also true for x = pi/2 in some sense
so no that doesn't answer my question
both sides are \textbf{defined} and equal for all $x \not \equiv \frac{\pi}{2}\mod \pi$
rafilou is not not born in 2003
so it is an identity on that set
oh
do we not specify what set something is a set on?
is it just uh retrieved from context?
whenever you have the identity f(x)=g(x), then the set on which that equation is an identity is usually the intersection of the domains of f and g
so here i would say the fact that this is true means that tan^2 + 1= sec^2is an identity at the level of functions because whenever it makes sense to talk about both tan^2(x) and sec^2(x) then that identity holds.
right i guess that is straightforward enough
i had the impression that the domain of the f has to match the domain of g
like uh if you rewrite the "identity" as: 1 + tan^2(x) = sec^2(x)
now both sides have the same domain
and then if we have x in R then rewriting the above identity as sec^2(x) - tan^2(x) = 1 😭 isn't an identity
but yeah i guess uh we need x for which both are defined
you can just restrict the domain of both functions if you want it to be a “true” identity, since g|_Dom(f) is another perfectly good function.
lol
so take g(x) to be 1 if x is not pi/2 and don’t define it otherwise
well i would say g is still 1
but like you might want to make the distinction that g is 1|Dom(tan)
How?
oh you mean like make some kind of continuous extension?
i mean the other way. restrict the domain of 1
like f(x) =1
oh i thought u meant extend the domain of sec^2 - tan^2 such that it matches the domain of 1
whoops
yeah i guess that's in some sense
the same 😭 as restricting the domain
it's just like x/x = 1 isn't an identity for x in R
yeah it’s a bit silly. but this actually does come up sometimes in geometry (like, the keyword here i’m thinking of is “change of chart maps”) where you want to talk about the composition of two functions but some of the image of the first function is not in the domain of the second, and that’s okay, just take the intersection where it makes sense.
same thing here but we’re talking about a relationship between functions, we have to restrict our domain a little bit.
yeah i guess i just i'll encounter that way later lol
for now i can live with this
cuz it just makes sense intuitively at least
So sin²x + cos²x =1 is also not an identity?
so basically an identity is just when f(x) = g(x) for all x in the intersection of both the domains, right?
it is
that's true for all x in R
.
huh
my point was that sec^2(x) - tan^2(x) is not an identity if x in R
but the other version 1 + tan^2(x) = sec^2(x) is an identity when x in R
in some sense at least
In mathematics, a partial function f from a set X to a set Y is a function from a subset S of X (possibly the whole X itself) to Y. The subset S, that is, the domain of f viewed as a function, is called the domain of definition or natural domain of f. If S equals X, that is, if f is defined on every element in X, then f is said to be a total fun...
I don't know if I am getting your point but I am fine with it
what do you not get though?

The thing I get is that sec²x -tan²x won't hold and just answer 1
Tell me if I am tru
when x = (2n + 1)pi/2
your equation clearly doesn’t hold
Oh yes I get now
I have just started functions before my grade
Just drawing graphs and stuff.
okay then, glad that’s sorted
anyway thanks everyone that helped 
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There is a theorem (idk the name) says:
in a the plane
if you have 4 points A, B, C and D
where A ≠ B
AB = CD (distance)
and AB ≠ CD (vector)
there exist a unique rotation that rotates A in C and B in D (or rotates [AC] on [BD]) which it's center is the intersection of the medians of AB and CD, and the angle of rotation is (AB, CD) [2pi]
Can anyone tell me its proof or send me a wiki link of the proof ?
I'll search and come back
I just guessed the name based on your problem but im not sure if thats what are you looking
is this related to geometry or linear algebra?
geometry
the definition I am working with is that: R is a rotation application with center I and angle theta
R(A) = B means IA = IB (distance) and (IA, IB) = theta [2pi]
Can you give full info or pic?
?
The thing i understand is that diagonal intersection is the rotation axis (R) and because ab = cd by symmetry the AR = DR so after rotating A and D will rotate on a circle so D will take A's place
I can't give written proof right now
Try to Google it by translating something should show up cuz it's a theorem
I tried for a long time searching but I didn't find
@oak granite Has your question been resolved?
vec(AD)=vec(AB)+vec(BC)+vec(CD)=veca+vecb+vecc vec(AC)=vec(AB)+vec(BC)=veca+vecborvec(CA)=-(veca+vecb) vec(BD)=vec(BC)=vec(CD)=vecb+vecc vec(AB).vec(CD)+vec(BC).vec(AD)+vec(CA).vec(BD) veca.vecc+vecb.(veca+vecb+vecc)+(=-veca-vecb).(vecb+vecc) = veca.vecc+vecb.veca+vecb.vecb+vecb.vecc-veca.vecb-veca.vecc -vecb.vecb-vecb.vecc=0
I am getting these results check this out
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first is the question, second is my answer, third is the solution
It's (2,3] because for i = 1 you have X_1 = (2,5)
You can't just take the limit of both endpoints and call it a day
In this case, the upper limit gets smaller, but so does the lower limit.
@wispy osprey Has your question been resolved?
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938c2cc0dcc05f2b68c4287040cfcf71
,, A \oplus B = C \iff A \subset C \quad B \subset C
938c2cc0dcc05f2b68c4287040cfcf71
i) a + 2 - 1 = 0
ii) a + 1 + 1 = 0
Damn bro u study so much give me some motivation how
the motivation is to finish my degree brother, dont you want to finish too?
Yes I do but the discipline is not the best🫡
thanks bro, gl u2 with algebra
@tidal turret Has your question been resolved?
what steps
That I told you for the previous exercice
There is no linear transformation in this exercice
But the steps remain valid
So, Step 1:
--> What are the dimensions of each space ? Is there an intersection ?
SnT is only trivial
dim S = 2
dim T = 2
Trivial as in null ?
yeah SnT = {0}
S (+) T = R4
I found a basis for R4
Tell me
,w Nullspace {{1,0,2,-2},{1,1,0,1}}
???
,w rref {{-2,2,1,0},{2,-3,0,1},{1,3,-1,-3},{0,1,1,0}}^T
Yeah but your basis should include (a,1,1,1)
S = <(-2,2,1,0),(2,-3,0,1)>
right
You're getting lost again.
but that is not in S
Yeah but forget S+T
We already established that's just R4
Now we're looking at the other side of the equations
This side
If you want this thing to be R4
You should create a basis for R4 that includes (a,1,1,1)
okay
that would look like this <(a,1,1,1),w1,w2,w3>
R4 = {(a,1,1,1),(0,1,0,0),(0,0,1,0),(0,0,0,1)}
,w det {{a,1,1,1},{0,1,0,0},{0,0,1,0},{0,0,0,1}} = 0
cmon you couldve done this yourself
Why did you equate it to 0 ??
oh, it should be nonzero
Anyway, you need that determinant to be different than 0 no matter the value of a
So your basis doesn't work
Try to have a determinant that is always positive for example
is a triangular matrix the determinant is the diagonal elements multiplied, det = a
Yes, but what we want is for the determinant to be strictly positive (or negative)
So the vectors you chose for the base don't give you that
Can you think of ways to change this matrix in order to obtain a strictly positive determinant (like a²+1)
If you find the matrix, you find the right basis
we know (a,1,1,1) ∈ S + T
The first vector should not be touched
forget S+T, we know it's just R4, so it doesn't add any information
I want you to change this coefficients (as simply as possible), to obtain a matrix for which the determinant is strictly positive
Try this
what?
Try this, see what the determinant is
(-1,a,0,0)?
but (-1,a,0,0) from where?
I wanted to make sure that the determinant was positive, like : a²+1
So I tweaked the second vector to make sure that's what I get
Here's exactly how I thought of it
I made sure det (A1) = a²+1 , because I knew det (A2) = 1
why do we want determinant positive
In order to build a basis, we need the 4 vectors to be free
no matter what the value of a is
So a way to build the 3 vectors is by looking at them like a matrix
So that means det of the 4 vectors can't be 0
yeah determinant of 4 vectors is NOT 0 because then we dont generate R4
yes
it can be positive or negative tho
you could also look for 3 vectors that are free, and orthogonal to (a,1,1,1)
but why positive?
We don't care about positive
the orthogonal complement of <(a,1,1,1)>
Strictly positive allows me to avoid 0
yeah that would work aswell
yes
W could be : ax1+x2+x3+x4 = 0
It would work as well
yes with the = 0
careful, don't divide by a, it could be 0
so it's solved
I always prefer to use the determinant cause it allows you to instantly check if vectors are dependant or not. No need to worry about any peculiarities
why is this soo hard
@tidal turret Has your question been resolved?
Is this not solved ?
@tidal turret Has your question been resolved?
how do I find a?
He’s not asking you to find a
He’s asking you to find a W that works no matter the value for a
Oh we did better than he asked
For the vectors I gave you, you can choose any a and it would still work
However
You can simplify by using a=1
Then the vectors you gave me at the beginning would work
@tidal turret Has your question been resolved?
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b basically represents all answers $n\pi + \frac{\pi}{4}$ where n is any integer
BuilderDolphin
if that's what was confusing you
Ahh no
(not saying it's the answer just clarifying it)
I meant is it working?
i mean
I understood its meaning
oh
well can a function have multiple outputs for a single input
then is b even an option
It violates our function property
You meant inverse function f(1)
Should have one value
So A is correct
yep
Hmm makes sense
i mean again can you get two outputs from one input
Not two
you're finding the value of the inverse tangent with input 1
I meant if my function is from (π/2,3π/2)
BuilderDolphin
$= arctan(1) = \frac{\pi}{4}$
BuilderDolphin
They didn't write the R-->R
Because tanx is not define
at π/2
And other
(2n+1)π/2
i guess i can see what you mean
no domain was given for tan so i just assumed (-pi/2, pi/2)
for arctan
but again that would violate the definition of a function
having multiple outputs
in that case yeah the inverse of $tan(x)$ in $(\frac{(2n-1)\pi}{2}, \frac{(2n+1)\pi}{2})$ at x = 1 would be $n\pi + \frac{\pi}{4}$ where $n \in Z$
What?
BuilderDolphin
So what option work?
the domain of tan would also depend on n
i would probably go with A logically since no domain is given but im no expert
depends on what ur learning too
B is correct if domain is specified in terms of n
but there isn't really anything related to that on the problem so i not sure
Can we wait for another helpers?
@orchid grove Has your question been resolved?
@orchid grove Has your question been resolved?
<@&286206848099549185>
Could you explain it?
bro, obv answer is b
u have to consider eery value of x that gives 1
since its an inverse
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What happens in the pink area?
inf/inf=1 ???
would you like me to show you that more general thing that i didn't get to show last time
sure but I have 20 minutes till exam so...
$\frac{x^2 - 4}{x^2 - 1} = \frac{(x^2 - 4)x^{-2}}{(x^2-1)x^{-2}} = \frac{1 - 4x^{-2}}{1 - x^{-2}}$
ann.in.a.teacup
the negative powers of x go to 0 and you are left with 1/1
because x once again goes to infinity
why did you add x^-2 in the middle part
i didn't add it
you multiplied by x^-2
i multiplied by it
the numerator and denominator are both quadratic
so i divided them both by x^2 so that their leading terms would instead be constants
and so that we don't have an infty/infty situation anymore
you can't divide inf/inf and get 1?
no
$\frac{\infty}{\infty}$ is undefined --- as shorthand for a limit (of the ratio of two functions, each of which goes to $\pm\infty$ by itself) it could be any number or even not exist at all
ann.in.a.teacup
case in point: if i slapped a coefficient of 2 on that x^2 term on the top (you'd get a different function), you'd get that the limit is 2 not 1
the negative powers of x go to 0
negative powers of x? X^-2 is something really small, like 0.0000...?
$x^{-2}$ approaches 0 as $x \to \pm\infty$.
ann.in.a.teacup
so does x^(any negative number)
that is what i meant with "negative power of x"
nothing more
oh I see
Could we split this fraction? Original one into two fractions? And then erase something?
this one
not worth the effort bc the denominator isn't a pure power of x.
what i showed just now is how you do it generally
can you turn x^2-4 and turn it into x^2-1-3?
then you could split and something would cancel
again
not worth the effort
you do not want to spend 17 years doing that with like idk 6th degree polynomials on the top and bottom both
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So I have $\int_{a}^{b} \norm{ f'(t)}dt$
\int
What a wonderful world it is !
Which is simply $\int _{a}^{b} \sqrt{2}dt$
are you sure?
what did you get for f'(t) itself?
What a wonderful world it is !
so $\sqrt{2} (b-a)$
What a wonderful world it is !
I'm interested in everything but part(a)
First to prove it isn't simple
$f'(t) = ( -3\cos^2(t)\sin(t), 3\sin^2(t)\cos(t))$
What a wonderful world it is !
The derivative is $(0,0)$ at $t = \frac{\pi}{2}$. It is thus not simple
What a wonderful world it is !
Now to come up with a piecewise paramatization
Could I define the piecewise paramatization as $(cos^3(t), sin^3(t))$ on $[0,\pi] - \frac{\pi}{2}$ and $(0,1)$ at $t=\pi/2$
What a wonderful world it is !
so the curve length would be $\int_{0}^{\pi/2} \sqrt{ (-3\cos^2(t)\sin(t))^2+(3\sin^2(t)\cos(t))^2}+ \int_{\pi/2}^{\pi}\sqrt{ (-3\cos^2(t)\sin(t))^2+(3\sin^2(t)\cos(t))^2}$
What a wonderful world it is !
Is that right
@twilit field Has your question been resolved?
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if $S = {u_1, \dots, u_n}$ is an orthogonal subset of an inner product space $(V, \mathbb{F})$ then how do i prove $S$ is linearly independent?
carburetor
since $S$ is an orthogonal set, $\langle u_i, u_j \rangle = 0$ for $1 \le i, j \le n$
carburetor
so i have $\sum_{1\le i, j\le n} c_i \bar{c_j}\langle u_i, u_j\rangle = 0$ or $\langle\sum_{i=1}^n c_iu_i, \sum_{j=1}^n c_ju_j\rangle = 0$
carburetor
0 = <ui, 0> = <ui, (...)> = ...
but doesn't this mean $\sum_{i=1}^n c_iu_i = 0$
carburetor
what are the c_i supposed to be if you didnt choose them specifically that way
you want to check lin independence
so given sum c_i u_i =0 you have to conclude c_i=0
c_i ∈ F i guess?
well yes of course the c_i are scalars
yes but that's not what i'm getting
i started with <u_i, u_j> = 0 for all 1 <= i, j <= n
for all i < j
not for all i,j
you have to take a step back
what is it that you want to prove
what is the definition of that thing
oh right
so therefore, how do you have to start the proof
then you can think about using what you know
@lunar pivot Has your question been resolved?
i think i got it
i can use the fact that $\langle u_i, u_i\rangle \ge 0$ to get something like $c_j || u_j ||^2 = \langle\sum_{i=1}^n c_i v_i, v_j\rangle$
carburetor
but $\sum_{i=1}^n c_iv_i = 0$ and $||u_j||^2 \ge 0$ which implies $c_j = 0$
carburetor
@runic hamlet this is fine right?
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Wasn't there some way of writing the taylor expansion as
$f(x)$ = $e^{\epsilon\frac{d}{dx}}f(a)$
kronium_
something like this
I dont exactly remember
Thats why im asking if someone knows
@somber canopy Has your question been resolved?
https://math.stackexchange.com/questions/185354/exponential-of-the-differential-operator
yeah you could do something like that
@somber canopy
yes
yes
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How would I prove that i is the derivative of d? Would saying they both have a vertical asymptote be enough, and if not, what else could I use to justify my answer?
you cannot give a proof as you do not know the functions exactly
you can also note where the function is increasing and tie that to the sign of the derivative
Thank you. Is there a proper way to word that saying that?
If I am reading it correctly I disagree with the proposition you make
“Intervals of increase/decrease”
Thank you
Autocorrect
.close
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I understand how to do it when its in standard form with 3 variables but i dont understand when its just 2 variables
It's the same process. Factor, make a sign chart, and test it.
x^2-2x=<0
How did you learn it?
what is a sign chart
we just put all variables on one side then you find 2 numbers that add to something and multiply to something
but I cant do that when there is just 2
Well, you literally only have to factor the x out with 2 variables.
That's it.
Maybe I can use desmos to demo
No pun intended
Here is a graph of the quadratic x^2-2x
ok
The shaded region is where the quadratic is less than 0
Where would you say this region lies between
On the x axis at least
I just dont understand how to factor x^2-2x=<0
I have only factored like stuff in standard form
You might need to revise a tiny bit
$x\cdot x-2\cdot x$ do they have a common term?
Bonk
What is a common factor in both x^2 and 2x
x
ok
You good from here?
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youre german?
chavez
I finished first midterm, still thinking about second exam, hopefully I am strong enough
Last time I got a 2/10 😅
when you do the questions here it looks like you do fine
do you get stressed during the exam?
I got adhd i think so 1h30 is usually not enough time to think through, when I do them here Usually is not under the clock
are you allowed extra time?
here youd get 15 minutes extra if you have some sort of condition
also in the exam the desks are so uncomfortable and the professors talk with each other and i can't concentrate bro
extra time students
yeah then ask if youre allowed some kind of extra time
look into your unis policy
I don't think they give a fuck
the professors talk with each other bro loudly like to make distraction
they want us to fail
then let them know to keep quieter
this is why I am studying with loud music so I simulate the exam room
they dont care bro, but i will consider it
is that a thing in your uni?
yea we humans will go extinct one day
@tidal turret Has your question been resolved?
dim(T) = 2 probably. Then dim(T) = dim(Im(f)) must mean the kernel of f, Ker(f) is of dimension 2, but the second condition says we have a direct sum between S and Ker(f) = to R^4, meaning dim(S) = 2 because you can sum dimension with direct sums. Then there should a value for a such that S is of dimension 2 not 3. For the last condition idk.
That's what I can think of without computing the things, I have to say it might not work. Yeah this does not look easy
right, you are gorgeous, thank u
you gave me a huge insight though thanks !!
@tidal turret Has your question been resolved?
@tidal turret Has your question been resolved?
@brisk iris
Y still need help with this ?
is tricky
Can I try to write it and send it ?
I think so yeah
The last vectors should be a vector of S
wdym?
I'm not sayuing it's wrog
But it's better if you use a vector of S here
Now to check, just make sure that all conditions are met and you're good
should be correct, thank you shaki
thanks
. solved
.solved
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bit of a silly question.
If we use two inputs, one to define the distance between each factor and one to define the start value (for example, x, 2 would be x double factorial) For convenience im going to just notate it like $F_{6}(x)$
is there a reasonable way to get something like... $F _ {4}(5) = F_ {5} (5)$ that isn't as cheesy 😭
