#help-39
1 messages · Page 325 of 1
God is
too bad
Sigh.
In slayla's thought bubble, it says she needs to be held. If you can offer her those services she might accept you
Are we still focusing on solving the problem.
Good point
@low kestrel did you need help in any other problem?
@low kestrel !done
Supposedly we are.
You should have factoid first, then ping.
Perchance.
You can see it didn't work.
Pass
what is going on here 😭
@timelord tbh l have more trigonometry problems that l need help with
If you know, you know
this is a psyop for me to do my homework
(i can help too!)
Guys, this is the 4th time for a redirection...
I don't unfortunately
no one knows twin
Please share
alright but l have a requst
She is too old for me, and too far away from me to hold. So I can't hold her.
Guys.
What is it?
Supposed to be metaphorical
l'm requseting all the people who aren't willing to discuss trigonometry to leave please
if you're here to make friends l request that you dm each other privately thanks
ok moving on
go ahead!! we are listening 
This was the request @wraith jacinth
-# oh ah i though it was an acedmic request oops coniute dont mind me!
mm, what about them?
-# okay what would u like to know about this? why they occor or what are they or when do they happen?? or do u want to understand why its these angels?
well can you all solve cos(45- 30)?
also, special angles referring to the 15deg, 30deg, 45deg, 60deg, 75deg?
we can! you use the cos(a-b) formula as timelord stated^^
special angles are only 3 , namely 45,30 and 60
And 0, and 90
ah, fair enough, how ive learned it they expanded it to include 15 and 75 deg
Maybe not special but still relevant
this might help-
-# also oops wrong reply dont mind me wjs
use the idea that cos(a-b) = cos a cos b + sin a sin b
so is there anyone who can use special angles to solve cos 720? it came in the end of term exam and mob guys were stranded
Do you know about periodic functions? Such type of questions could be solved by using periodicity of a function.
well we can simplfy the angle first!
This is basically it. Also there are formulas for cos(x+90k) where k is an Integer
this is bassicly because every 360 degress corect me if am wrong this circle repeats
cosine and sine have a period of 360deg
all this means is that if you have, say, sin(a) you can add or subtract whatever number times 360degrees to a, and still get sin(a)
so we would do atotal of two revolutions 720-360 and then 360 - 360
this gif here might help and as u can see the angle (the exaxct nubmer is seen at the top)
notice how when we cross the 360 degree mark we starts over
so forexample if i gave u an angle of cos(370) is it the same as cos(10)
does that make sense so far?
||-# hey, sorry, i dont take unsolicited dms due to preferences and other reasons, but yes, i did make the guide myself and so on||
100%
Yes I found a mistake in it
okay so u can imagne how removing the 360 from the angle can help!
so for example try it if i give u an angle of cos(400) = cos(x) can u tell me what we can use as x here instead of 400?
I sent you the mostake. You dont have to respond if you dont want to
40
yup exactly!!
yayy!!
so if i give you an angle of cos(720) can u solve this now?
-# like cmon justopenur ownhelp channel atp or go to #serious-discussion
You can remove or add 360° as much as you want, until you get whatever you want in parenthesis ( or something very close to it, or something you already know. )
cos 720 = cos 360 but using special angles how should l calculate that?
well here is the thing what does cosine and sine really mean?
cos = adjacent over hypotenuse and sine = opposite over hypotenuse
You could remove another 360°, you do realise that?
sohcahtoa
another good visualisation is using the sine and cosine graphs! this graph is in radians, and 2pi is 360degrees, but this shows that the output of sin(a+k*2pi) where k is some integer is basically the same as sin(a)
okay so for sin u can say it is the Ratio of how big the (the side opposite to the angel is COMPARED to the hyptonuse)
mhmm
so notice how when we increase the angel what happens to the hieght here?
but if we subtract another 360, hen we would get cos (o) is that acceptable?
using this idea, we can rewrite cos(720deg) as cos(a+k*360deg), and we know that that is also equivalent to essential cos(a)
yes!
wait wait- if u understand cos and sin u wll understand what this means
so here look at this notice how when the angle (on the left shown by blue green and light blue) gets bigger the (hieght) gets taller?
lmk if anything does make anysense at any point-
-# well, yes! cos 0deg is the same as cos 720deg!
-# they are essnetaily the same because if uturned around 0 degrres and 360 degrees and look at where ur looking in both cases it wouldbe as if u didnt move at all
so bassicly sin describes the hieght relative to the angel
this is why if u imagne increasing that angel until its 90 (Degrees) you would notice that both the hyptonuse and the hieght would be exactly = therfore once
But if u reduce the angel all the way down to 0 u will notice that the WIdth is what is = the hyptonuse now
this is why sin (90) = 1/1 so 1 and cos (90) ((remeber cosine describse adj which is width here)) would be 0
followning this logic can u guess what would be the width (cos) at angle 0 ?
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yo so
The derivative of x^3 is not 3x
blud got hacked
oh my god
what is wrong with me
but then can you just use uhh
wait
im thinking
do i use 0 and 4 as boundaries
but how do i actually get the triangle area
shit man
yes im
sure 0 and 4 are the boundaries, but
If you find the point where they intersect you'll get the height of the triangle pretty much instantly.
The tangent line and g I mean
yup but
i mean
And then your base is between the two x-intercepts.
oh
oh shit yeah
but
wait so i just integrate the lines only
You don't really need to integrate anything.
The triangle's base is on the x-axis delimited by the x-intercepts of the lines, and the height of the triangle is given by the intersection
damn
man they just like to do some weird stuff
so 2*intersection/2
is my area
i got another problem i geniuenly do not understand them
so here i basically tried drawing it in
it does look like its the midpoint all the time but like
if you put 0 in then its 0
ill open a new channel
.close
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can i get help with exercise 10
You need to show it's regular first.
Can you take its derivative and check that it's nonzero?
its an integral
you mean ftc1?
You need to check that $\tilde{\sigma}(s)$ is regular.
Azyrashacorki
yes, you can use this theorem
how
Consider the new parametrization they give you, differentiate it using the chain rule, compute the velocity.
but is an integral
in your case g'(t) is literally the definition of this theorem, the derivative will simply be the function under the integral (the norm of velocity)
In other words:
Modus
Just use the chain rule. $(\tilde{\sigma}(s))' = (\sigma(g^{-1}(s)))' = \sigma'(g^{-1}(s)) \cdot (g^{-1}(s))'$. Now figure out what $(g^{-1}(s))'$ is with what Modus gave you.
Azyrashacorki
can we start from the scratch I dont think I follow
You need to show that the parametrization given by $\tilde{\sigma}(s) = \sigma(g^{-1}(s))$ is regular. To do that, differentiate it as above to figure out what the velocity vector is.
Azyrashacorki
Once that's done, the second part where you show the parameter gives the arclength is instant.
This will involve finding an expression for the derivative of $g^{-1}(s)$. There is a rule for differentiating inverse function you should know.
Azyrashacorki
yes
inverse function theorem
Good, so what's the derivative of g^(-1)(s)?
it should be 1/g'(g^1(s))
Okay, and what is g'(g^(-1)(s)) given how g is defined?
No
sigma hat
Well now that we know $(g^{-1}(s))' = \frac{1}{||\sigma'(g^{-1}(s))||}$
So now what is the velocity of sigma hat?
unsure
Azyrashacorki
What is sigma hat?
sigma circ g^-1
So how do you differentiate the composition of functions?
⛓️
function composition rule for derivatives
@summer imp
Okay, so you have $(\tilde{\sigma}(s))' = \sigma'(g^{-1}}(s)) \cdot (g^{-1}(s))'$
yeah, what about sigma hat
Azyrashacorki
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
And what was g^(-1)(s)?
there is some error with the latex @summer imp
Yes it's still right.
Okay, so you have $(\tilde{\sigma}(s))' = \sigma '(g^{-1}(s)) \cdot (g^{-1}(s))'$
Renato
It's just an extra curly brace
what about it?
Well this is meant to be the velocity of sigma tilde.
But you found an expression for the derivative of g^(-1)(s) earlier
$(\tilde{\sigma}(s))' = \sigma '(g^{-1}(s))\frac{1}{\norm{\sigma'(g^{-1}(s))}}$
@summer imp
wdym
.
Renato
Well what is the magnitude of this vector?
I believe is normalized
how
right
no
Right, so then that parametrization is regular.
what
The velocity vector is never 0, so it's regular.
Now use the definition of the arclength to compute the arclength between 0 and s of this parametrization.
which parametrization thou
Sigma tilde
The whole point is to show that the arclength of sigma tilde between 0 and s is s.
We didn't normalize it. The velocity is normalized by definition
It's from how sigma tilde is defined
okay
anyways to find the arclength of sigma tilde between 0 and s
I need to differentiate sigma tilde once and find its magnitude
so the integral of the magnitude of the velocity of sigma tilde right
@summer imp
Yes. You've already computed the derivative of sigma tilde though
when?
in here
?
but I need the magnitude of this right?
so $\int_0^s \norm{(\tilde{\sigma}(s))'} ds = \int_0^s \norm{\sigma '(g^{-1}(s))\frac{1}{\norm{\sigma'(g^{-1}(s))}}} ds = \int_0^s 1 ds = \left[s\right]_0^s = s$
@summer imp
What is the magnitude of a normalized vector?
1
Renato
@summer imp like this ?
Yes like this
The way sigma tilde is defined makes it parametrize the same curve, but with speed 1.
Then it's regular, and by definition the arclength between 0 and s is s.
What do you want to rewing to? That's pretty much all you did.
You computed the velocity of sigma tilde, found it was normalized and thus had constant speed 1.
yes
we basically proved that g'(t) is always 1 for all t in T
@summer imp
No, that sigma tilde' has speed 1 for all t.
g'(t) isn't 1 it's the speed of sigma'(t).
sigma'(t) isn't normalized
can we start from scratch?
it was a long amount of steps, first we used tfc1 on g(t) in order to find g'(t)
after that we get that g'(t) is the magnitud of sigma'
but where is sigma' defined
@summer imp
Sigma is some parametrization.
There aren't that many steps.
You want to show sigma tilde is regular, so you compute its velocity using the chain rule and FTC1 for the factor that pops out.
This turns out to give that sigma tilde' is normalized, so has speed 1.
,, g(t) = \int_a^t \norm{\sigma'(\mathcal{T})} d\mathcal{T} \ g'(t)) = \frac{d}{dt} \int_a^t \norm{\sigma'(\mathcal{T})}d\mathcal{T} \ g'(t) = \norm{\sigma'(t)} \ (g'(t) \neq 0 \text{ , } \forall t \in \left[a,b\right] \implies (g^{-1})^{'}(t) = \frac{1}{g^{'}(g^{-1}(t)} \ (g^{-1})^{'}(t) = \frac{1}{g^{'}(g^{-1}(t)} \implies (g^{-1})^{'}(t) = \frac{1}{\norm{\sigma' \circ g^{-1} (t)}}
@summer imp
after applying fundamental theorem of calculus 1, then we are being told that forall t in T that g'(t) != 0 so we can use inverse function theorem
right?
Yes
@summer imp
Renato
like this
anal 2 si
jajajaja que coincidencia
recien empezando jeje
es dificil, tenele paciencia
yy pega un salto
igual tene en cuenta que estos ejercicios son para que entiendas conceptos, no te van a tomar nada asi en un parcial
esto era guia 1 si no mal recuerdo
y si, ando re atrasado mal
siempre es primer parcial con algo de parametrizacion, segundo de green, tercero stokes y cuarto gauss
ando priorizando taller de calculo avanzado
no se si seguira siendo asi
banqué totalmente, yo estoy en datos pero se ve en analisis avanzado esas cosas
algunas nociones y demos de analisis 2 las vas a entender mas faicl sabiendo tca
perdon te re ocupé el canal
si queres hablame al dm
te dejo seguir
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is a negative number prime?
like -5,-7 ?
technically not?
well. i was solving an inequality, and they asked number of prime numbers satisfying that inequality. the boundaries are
$$(-\infty, -2.5) \cup (-2, 8)$$
TheAstorPastor
so i just have to include +ve ones right?
yep
hmm
in some book, i saw them to be -ve
Hungerford's Abstract Algebra: An Introduction
i think
the classical definition exludes negative integers (among other things, due to the factorization of numbers), so negative numbers do not enter
hmm
ok
.close
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Consider $\Phi ( r,\theta,\varphi ) = (x,y,z)$, the usual map from spherical to Cartesian coordinates. The domain of $\Phi$ is the $3$-cell $D=[0,1]\times [0,\pi]\times [0,2\pi]$. Is this map $C^1$? There's an example in Rudin's book where he integrates $dx\land dy\land dz$ over $\Phi$, but this integral is only defined for a $C^1$ $3$-surface.\
What makes me uncertain is that Rudin comments "... that the mapping is 1-1 in the interior of $D$ (but certain boundary points are identified by $\Phi$) ..." What does he mean by this?
psie
@wind lagoon Has your question been resolved?
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yo i hate fucking hate math
how do i even approach the event D
is this the entire problem
no but like generally
ik the bernoulli formula
were allowed to use calculators for this but
just send the entire problem
yeah
now you hvae 16 people reimaining
and out of these 16
5 choose salad
so you can have something like
so
(s,s,s,s,s,notsalad,notsalad....)
or
(s,not s, s,s,s , nots, nots,...)
any combination
of 5
from 16
nah
ok lets take this case
whats the probability for this
1/3^5 + 1/3^4
i mean other exponent
this is correct
oh yes right
so
lets take this case
( salmon, salmon, salmon, salmon, salad, salad, salad ,salad, salad, notsalad, notsalad,...(in total 11 notsalads)
whats the probability for this
wait its 4 salmon
what about the not salads
whats P(notsalad)
2/3
7
( salmon, salmon, salmon, salmon, salad, salad, salad ,salad, salad, notsalad, notsalad,...(in total 11 notsalads)
yes
1/3^4 * 1/3 ^5 * 2/3^11
but remember
this was jsut 1 case
( salmon, salmon, salmon, salmon, salad, salad, salad ,salad, salad, notsalad, notsalad,...(in total 11 notsalads)
we can arrange the salads in any way we like
not necessarily the first 5
out of 16
the salmon never changes though
cuz it says so in the question
so
only the 16 change
right?
wdym only 16 change
yep
nah
its something with ! right
yeah
but idk how
hast du schon mal von "Binomialkoefizzient" geheort
yeah
so 16 5
yeah
is it just 16!/5!
oh damn
Der Binomialkoeffizient ist eine mathematische Funktion, mit der sich eine der Grundaufgaben der Kombinatorik lösen lässt, nämlich auf wie viele verschiedene Arten man aus einer Menge von
n
{\displaystyle n}
verschiedenen Objekten jeweils
k
{\displaystyle k}
...
so you have this 1/3^4 * 1/3 ^5 * 2/3^11 and this many options 16! / (5! (16-5)!)
and you just multiply them together
so
1/3^4 * 1/3 ^5 * 2/3^11 * 16! / (5! (16-5)!)
,w 1/3^4 * 1/3 ^5 * (2/3)^11 * 16! / (5! (16-5)!)
yeah
oh damn
so 0,257%
you dont usually need to memorize it
cuz you have the C button on the GTR
and you just plug in (16 5)
but yes i memorized it after using it for quite a while
,w 16C5
bro
look
do yk the vierfeldertafel
yeah
thats always conditional probability right
um
not really
i mean
kinda
it depends what you mean
every square is P(something AND something else)
to get the conditional prob you need to take this square and divide it by the outside square
cuz the formula is P_B(A) = P(a und b) / P(b)
damnn
and you find P(b) on the outside
man i gotta learn some other stuff now holy shit
why did i study so late im so stupidd
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Can someone explain what reordering a sequence/series means and how it can affect the limit
I saw a basic explanation on the fact that it doesn’t seem to affect the limit of a sequence because a sequence is essentially a set and sets don’t really care about the order of elements anyway
Now how is that different for a series
And how would I reorder a series to tend to any limit
I have a specific problem in mind but I’d like to figure out how everything works first
Maybe with simple examples
@left anchor Has your question been resolved?
just show your specific problem
Asking the actual question right away is more likely to get responses.
Asking "Can I ask...?" or "Does anyone know about...?" doesn't give people enough information to decide whether they can help, and answering can feel like a promise to help with the actual question, which they might find themselves unable to.
This is the main part I’m interested in I was hoping it’d be clear enough
I can post the actual problem too but I wanted to make sure that I understand the concepts well enough in advance hence the questions
yes post the actual problem
Working on it
Need to take photos of the necessary parts and explain
I have this series which converges to 0 but it is not absolutely convergent (is that the right term?)
All the problem asks for is reordering it to converge to 7 instead while maintaining the given structure from the photo
<@&286206848099549185>
@left anchor Has your question been resolved?
@left anchor Has your question been resolved?
Normally when you add up numbers, the order you do so doesn't matter and you get the same sum regardless. And, of course, the same holds true even if you add up infinitely many numbers.....
Right?
=Chapters=
0:00 - Let's rearrange a sum!
1:48 - Investigation
6:32 - Riemann Series Theorem explained visually
13:58 - Resolving objections
18:52 - A...
Something like this?
Yes
Changing the order of addends to get a different sum
Maybe this video will help, or did u already watch this
I’ve tried doing research by myself in the meantime and found the Riemann rearrangement theorem
Not that specific one
Its a great watch
Now I’m still struggling to understand how I would do that for a specific series
The key concept of going back and forth by adding / subtracting numbers around the limit makes perfect sense
But how do I define the series to do that?
I’ll open it up thanks
.close
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I've been struggling at (ii) for so long
So we get f(x+h) > f(x-h) for all x and sufficiently small h
but how do I go from this to f being strictly increasing?
I've been considering an approach similar to using the mean value theorem but it's not been working
@inland ivy Has your question been resolved?
<@&286206848099549185>
I think I did this with contradiction
f^s is just f', no?
So you just need to prove that f is strictly increasing when f' > 0
Which, I'd be surprised if that's not just a theorem in your book
We can't assume differentiability though right
f^s existing doesn't imply f' existing
yeah that's the point
consider , on (0,1)
$f(x)\begin{cases}1 &x=\frac{1}{2}\
x&\text{otherwise}\end{cases}$
I've been trying to
Ah the if. Didn't see it
qwertytrewq
this is not continuous
this is a counterexample i think
yeah so continuity is critical here somehow
what grade level math is this
it's first year uni
I can give you a hint, assume for contradiction that there exist c, d in (a, b) such that c < d and f(c) > f(d). Then choose any y in between these function evaluations and define the set S_y = {x \in [c, d] : f(x) >= y}
what the blud
i think contradiction should work. Let f(a)<f(b)\geq f(c) with a<b<c. Find the maximum of the function on [a,c], and f^s should be weird there
the continuity comes into picture when you show that ||f must possess an uncountable number of strict local maxima||
this is what I thought but you can't really say much about the symmetric difference even at the max
😭
all I'll say is good luck bro
how so? eval at -h and h must agree no?
symmetric quotient always agrees, it's an even function
i dont see how f^s isnt going to be 0
oh wait
mb it could
if I take z = sup(S_y) then by continuity f(z) = y and f(z-h) >= y > f(z+h) for sufficiently small h
but then f(z-h) - f(z+h) > 0 which is a contradiction
does this work
okai youre kinda in the right way ig.
mvt does NOT work directly cuz f isn't necessary differentiable thr cheat code here s to assume for a sec that f has local max and if it did f^8 (x) would have < or = 0
which contradicts the given f^8 (x) > 0
so f cant have local maxima or minimum which forces it to be strictly mono. since f( x + h ) > f (x-h ) it has to be increasing ig
hope this helps
why does f having a local maximum force the symmetric derivative to be <= 0
oh my god i hate this fucking problem
at a local max the function has to stop right? and turn back down so if f(x) is a peak then f(x+h) and f(x-h) are both similar then the peak so when you subtract em in the sym derivative formula youll NEVER get a + result it will be < or = 0
since our f^8 =is strictly > 0 a peak is literally impossible it has no choice but to keep going up
@rustic tendon can you just give me the answer i've spent too long on this
consider x when x<0 and -1/2x when x>=0
0 is max
but the symmetric derivative is positive at 0
yeah f can decrease slower on the right than the left, so f(x+h) is still > f(x-h)
u have, in the derivative formula (-1/2h-(-h))/(2h), the limit is 1/4 i think
why must f(z - h) >= y
I just got left my room for a break 
well for any delta there exists h < delta with f(z-h) >= y
but that's not enough i realise now
see but you're getting there
wait it's still a contradiction right??
f(0) =0 then f(h)= -1/2h and f(-h)= -h ---> into the formula (-1/2h -(-)) /2h = (1/2h)/2h =1/4
so even with a shrp peak at 0 f^8 is still a 1/4 which s >0
@vital crescent
because you need f(z+h) > f(z-h) for ALL sufficiently small h
but you can always find arbitrarily small h with f(z-h) > f(z+h)
which is my point no? u claimed that at the peak it should be <0 or =0
but thats my whole point since ur examples symm derivative @ x = 0 turned out to be 1/4 which is > 0 it proves that x=0 isn't actually a local max in the context
a true local max would require f^8 (x) < or = 0
if the f^8 is strictly + everywhere a peak literally cannot exist lol
then how does f not having local max and local min (where they are defined in your context, not the actual local max/min) imply that it is monotone?
if u define critical points to be such that f^s at the point must be 0, then I feel like this is merely a restatement of the original question
its basic calc bro if a continuous function on an interval doesn't have any local max or min it literally can't turn around
if it starts going up and never hits a peak to turn back down
it has to stay strictly increasing
u r using the definition of actual local max/min
u said here the local max is "in your context"
this is my function
x=0 is, in the usual sense of local max and min, a local max
symmetric derivative is >0 at 0
but u claimed that it isn't a local max in your context, which I dont understand. If tou change the context of what local max/min means, youd have to reprove the statement that no local max/min implies monotone
mhm
so the issue sort of is that what if, every where, the function looks like this (it sure will be some weierstrass like function)
By the statement it can't exists but it's not immediately obvious
okai look im not changing the def of a local max but if s f^8(x) > 0 for all x then for any point x0 the function MUST be higher at x0 +h than at x0-h for small h this property alone makes a local max (where a point is higher than its neighbors on BOTH sides) impossible und in calca if a continuous function has no local peaks or valleys to turn it around it has no choice but to stay strictly monotone in this case increasing right ? its a standard result for symmetric derivatives so no need to overcomplicate the definitions ig
this property alone doesn make it a local max as illustrated by my example tho
i gave an example where it is local max ( in fact a global max) in the usual sense, but at 0, the symmetric derivative is 1/4
the f(x+h)>f(x-h) is always true using my function at x=0
u could have all these properties while not stopping f(x) being greater than every single one of those f(x+h)
If it were f' then sure all that you said is true. But it is f^s, and f^s does not directly compare f(x+h) with f(x), which is where the issue lies
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Hello im struggling with finding which of those answers are wrong... I've looked over and I can't figure out which one is wrong. It says atleast 1 is wrong.
you on your own
how come?
Okay, so, do you recall the definition of a line integral over a vector field?
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✅ Original question: #help-39 message
not the full definition to be honest but like i used it for circulation and flux and masses. Since those are the formulas I have
wait no thats just for line intrgals... not over a vector field..
Thats how you do the calculation, visually, it has to do with tracing the dot product of the field with the direction of the parametrization.
wikipedia has this quite intuitive gif.
So you go about the curve using r', evaluating the dot product at each point w/ the vector field, and finding the acumulation of this value.
Notably, you have to know how the dot product works
I want to believe youre familiar enough with it.
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I’m not sure what to do for b and c
,rccw
(hint: say, does x = 50 make sense for this problem? why (not)?)
what function did you get for part A?
V(x)=40•12•x? Idk if that’s what you r looking for or not
ouch thats wrong
I thought l•w•h is the formula for volume?
yeah but we are cutting the lengths and breadths so they could turn to heights
Oh would it be 40-2x or smth? And then12-2x
exactly
now what would be V(x)?
can you visualise the maximum possible value of x we can take such that the box still has non zero volume?
Wdym visualize
like for eg in the given diagram taking x=0 and gradually increasing x
I’m not really sure how to do that in my head
(or, if I may interrupt, you can try an extreme value like this and see what happens physically.)
I’m really confused 😭
in that case, sorry for interrupting. I'll let Itsuki continue.
I just don’t know how to approach b liek what math to do to get an answer
can you have negative length
So it’s above 0 and not including so (0,_)
Oh wait
Could it include 0?
I don’t think so
Would it be (0,10)?
WAIR
technically we could have 0 (flat, so not really a box)
(0,11.8)
40 and 12
no
(reference image)
40-2x and 12-2x
correct
Can I just make them equal to zero to solve?
yep!
So I got x=6 and x=20 but what one do I put in the domain
so anything between 0 and 6 should work right?
because all the side lengths would be positive
Yea
It would make the side length to big
could those work?
okay you're right that it wouldnt work
but for the wrong reason
To small?
if i took something like 10, then 12-10(2) is -8, and we would then get a negative side length
i just want you to understand why stuff past 6 wouldnt work
anyways, we have our domain 0 to 6 now it looks like
can you carry on with the rest of the problem?
Yea but go c I’m stuck I know I need to isolate smth but u do not know what because there’s only x in the volume equation
also, im sorry for taking over @timber cape , please carry on
you're both doing great
its okay, sometimes i feel like observing more experienced people is better than just self trial and error
no worries, you wanna take over for c? im gonna go back to studying, just taking a little break
do you remember the concept of derivatives?
We haven’t done derivatives. I asked a question earlier and the person was surprised the way my teacher did it. We do it with like graphs and finding maximums and minimums
Not the same problem but yea
I know I’ll likely have to find the max on a graph
yes you can try the same logic but the function here is a bit worse
-# it will work but will take forever
if you want, i can show you the derivative approach at a glance
-# ill just show the derivative approach anyways
basically, the derivative or slope of a function y= f(x) (in this case V(x)) is equal to dy/dx
for a maximum/ minimum, the slope needs to make 0 degree angle with the horizontal(x-axis)
I caved and look at the answer key and I was overthinking it all I had to do was put the equation I already had into my calc and find the max 😭
damn
I just need to get at least like a b on this test at this point I’m a senior I’m checked out
like I got 13 days left… college won’t reject me if I get a b in math
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Let $P(x) = x^{2026} - x^{2025} + ... -x+1$.Does there exists a sequence of integers $1 \le a_1 < a_2 <... < a_{2027} < 2027^{2027^{2027}}$ such that $\ (i)$ $a_i | a_j$ for each $1 \le i < j \le 2027 \ (ii) P(a_i) | P(a_j)$ for each $1 \le i <j \le 2027$
Copter
i dont really have many ideas other than using a - b | P(a) - P(b) or factoring P(x)
Copter
<@&286206848099549185> ;-;
Maybe try finding $a$ and $b$ such that $P(a) \mid P(ab)$
Erebus
hmmmm
@north talon Has your question been resolved?
@north talon Has your question been resolved?
Do you perhaps know the source of the problem?
no
Are you doing question a, right?
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I calculated.
A = 35°
B = 64,33°
C = 80,67°
a = 35
b = 55
c = 60,21
but apparently there are two solutions??? Explain please don’t y’all start to yap.
It’s 3.
What do you need to find, given a,b and angle A?
Would you mind translate the question?
have you been introduced to the ambiguous case for sine rule
@winged pulsar Has your question been resolved?
I already founded it
Great, any more questions?
BUT THERE ARE FOCKING TWO ANSWERS.
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what is p(x)?
i have no idea too
nothing liem that?
whaddafuq
oh it actually means f(x)=px…
why couldn’t they just write that bru
anyways
@swift spindle Has your question been resolved?
horrible abuse of notation.
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I looked at the memo and I don’t understand why they kept the 90-3x
memo as in the stuff in blue?
The first line in blue seems wrong. its supposed to be sin(90-3x) not cos(90-3x)
Why le
Also you cant just divide by sine. you "cancel" it
*pls
complementary relationship between sine and cos
cos(t) isn't the same as cos(90 - t)
I looked at the memo and I don’t understand why they kept the 90-3x
Wdym
Huh
Your going to have to be more specific. What are you confused about
What they said
90-x appears again in the following line
But what is your issue with that?
do you think it shouldn't be there anymore or that it should be something else
Yeah
Firstly, do you have any issue with the first line
sin(2x-20) = sin(90-3x)
No
For the next step
What do you think it should've been, and
what law/property are you applying
Also you cant just divide by sine. you "cancel" it. This is done by taking the inverse of both sides
How pls
Its a bit complicated, but essentially:
sina=sinb
arcsin(sina)=arcsin(sinb)
a=b
This isn't always right due to the period of sine
they're applying the periodic property of sine to get the general solution
Wha
note that
sin(t) = sin(t + 360°)
you've done plenty of problems related to that this past week
or more generally
sin(t) = sin(t + k * 360°)
exactly what followed in their work, they split it into two cases
First case was a direct application of the above
If sin(a)=b, arcsin(b)=a
you mean doesn't get affected?
Yes
k represents some integer
could be positive or negative or 0
so when representing a general solution, the sign before doesn't matter
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Can someone walk me through some problems
!da2a
Asking the actual question right away is more likely to get responses.
Asking "Can I ask...?" or "Does anyone know about...?" doesn't give people enough information to decide whether they can help, and answering can feel like a promise to help with the actual question, which they might find themselves unable to.
!status
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
let's start with q1
Ok
quick
?
1
2?
^4 ^5
where do you see ^5
Hello
Kind of
how many terms are there
3
4, 3, 2 1
^4
X^4
Degree?
yes
Yay
This is the original problem right?
h-
-# time lord how are you awlayws one step ahead lol
Hehe. I have future sight
Cool
because he is literally time lord?? 😭
-# you truly are a time lord
you fell right into that one xd
…
But still hat question are you stuck on
Number 3 in the image
Ok
So do you know how to group the terms
Essentially you need to group the terms with the same variable and exponent
Basically, you can group 9x and 4x because they have the SAME variable with the SAME exponent
so bassicly grouping terms is like grouping same type of objcests together like having 10 squares and 5 circles and 2 squares and 8 circles
so in total u have how many sqaures and how many circles?
-# would recommend expanding first
So @zinc zenith take the third question and expand the bracket
No problem. When your device is charged we can continue
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Hello guys. What is the point of finding the maximum of a function by finding the point where the derivative is 0 if you can just use the vertex maximum formula?
the vertex maximum formula only applies to parabolas
a circle is not a function
Aka two points where dy/dx = 0
a point where the derivative is 0 can be a maximum, or a minimum, or neither
I see
So what else has a maximum?
many continuous functions have a maximum
Alr
sin has a max of 1
@willow wren Has your question been resolved?
Got left on read but ig
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hmm
How can I proceed further from this step
Yes
x is an integer here,right?
Yes
um. [4]
4
Yes
Yes
now {x^2} must be 0 as well
Yes
Yes
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