#help-27
1 messages · Page 345 of 1
this is slightly off topic but if i worded this as an answer would i say "the lockers left open have an odd number of divisors out of 1,2,3,4 and 5" or is the last part with the "out of.." wrong
why out of 1,2,3,4,5? there are 100 students
The easiest way to find them are to follow the perfect square numbers from 1 to 100
because it would be irrelevant if the number was divisible by 12 for example because it only matters if its divisible by 3 4 2 and 1?
but we are tallying all possible divisors? 12 could be a divisor of the number 24, for example
i seee
7 is toggled twice, but the number of divisors out of 1,2,3,4,5 is odd
so you see, there is a mistake with this only consider 1,2,3,4,5 characterization
I think 🤔 BCOS only perfect square have odd numbers divisors
yeah thats what we are trying to guide them to do
its important to see why though
i do understand i think
can you try proving it?
because usually numbers have an even number of divisors
and because square numbers have 2 of the same divisor
then it becomes odd
because you subtract 1
why so?
because prime numbers have 1 and themself so thats 2 and composite numbers have 1 and themself and have to be even because the 2 divisors will be different if its not square
sorry if thats hard to understand
like 21 has a factor of 7 but it also needs another factor because it sint square
the other one being 3
I don't think this argument is formal enought to even begin judging the correctness
sorry
27 has a factor of 3 and no other prime factor
yet its not a square
ok but then how do you show that its even though?
normally you'd pair up the divisors, but I don't see you pairing them up
yes!
The key thing to note is that this pairs every divisor that is strictly less than $\sqrt n$ to a divisor that is strictly greater than $\sqrt n$
qwertytrewq
then can you explain the argument?
because when you divide it by a divisor you get a pair of 2 factors like 16/2=8, and then the next divisor is 4 which is the square root after which would just give the pairs in reverse like 16/8=2, and since every number has at least one pair, like prime numbers have 1 and themself, only square numbers will have an odd number of divisors because they have 2 of the same
sorry if the explanation is like
rambly
idk how to really do them
or if i was explaining the right thing
so i tried to do both
yeah that is roughly the argument, one need to justify that the pairing is unique: in the sense that if (a,b) is a pair and (b,c) is a pair, then a=c. So in this way every pair are disjoint. But all those are not too hard to write down the details of.
and that this pairing gives us a way to count all the divisors (except when it is a square, and the pairing contains a pair (a,a) so we are counting a twice)
i think so!
thank you !!!!!
np
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simple thing to solve but I’ve never learned about it
what's the question? find the shaded area?
yea
do you know the area of a fan?
try expressing it as the area of the circular sector minus the area of the triangle
?
like how to calculate the area of a fan?
are you being sarcastic or
section of a circle...
^
it is ok, do you know how to calculate the area of the fan
would it be safe to say that the sector of the triangle is 60
wait
sector of the circle is 120
sorry
nah nvm, I don’t even really know where to start
area of a sector bro
well can you find the area of the whole circle?
the sector is 1/6th of the circle, right?
(pi)r^2 is the whole circle
ok
what is 1/6th of that
yeah that is right
now you have the area of the sector, what do you need to find out the shaded area?
good, do you know how to do that?
alright prove that to me
Equilateral triangle
good
60 60 60
no
how do you solve for that then?
alright
And then
ok good
306090
good
yes nice
now you have base and height, you know the area of the triangle
finally, what is the area of the shaded region?
But wait before that, sorry but how would I do 6 root 3 x 6
you dont know how to do that?
6root3 is basically 6Xroot3 X6
yeah weird numbers are right
does the question ask you to round or give exact answer?
^that is not how you notate exact answers
if you do exact answers:
never multiply anything by pi (aka leave 24pi as it is
Ok
never break a square root (aka leave 18root3 as 18root3)
So the answer is 6 root 3 x 6 - 24 pi =- shaded region?
sorry shouldnt be 18root3
Ah ok thanks so much
do A=24pi-36root3
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Find the equation of the normal to the parabola y²=-8x at (2, 2) in the standard form.
basically this question came in our last year annual exam and i am convinced this question is flawed, the point doesnt even exist on the parabola, further more the exam marking notes state a totally flawed approach of basically derivating the parabola and then getting the slope at a place where the parabola doesnt even exist, honestly i just want someone else to verify this for me, but i am like 99% sure the examiners messed up
is there a tangent line of the parabola passing through (2,2)?
nope, the parabola is on the left side of the origin
while the point 2,2 is on the right side
the red line is the slope point line from 2,2 and the slope from the parabola at 2,2 doesnt exist
hmmm you could make a normal line that contains (2,2)...
though it would be a bit problematic because you dont know the intersection
i.e. normal point to find the slope
you could find it maybe...
exactly
so did you do as much?
heck, the exam probably doesnt even have enough space for all that working
😢 it is what it is
did u take a look at the "better response" image
.
💀 y=2? huh?
well i have my my exam tomorrow, this was from previous year's past papers, i am practicing on them
i hope smth like this doesnt come 😭
well erm
good luck on
analytic geometry then 💀
the y=2 thingy
is faulty
not faulty, it just has no basis
wrong solution
its wrong
this has two slopes for two possible tangent lines though
i switched x and y because why not
to convince yourself its wrong find the tangent using that normal
yea and i dont think our syllabus covers finding normal from parabola which contains (x,y)
i tried asking gpt for help and it gave a super long and complicated answer
yeah ts problem is too long relatively speaking
and the given solution js
wrong
yeah definitely we should do that
❎
anywayss thanks alot guys
but you do understsnd how to obtain the actual solution right?
honestly speaking, no 😭
you use an arbitrary point which has the slope of normal equal to slppe with (2,2)
thats it
then you get the slope and then you use (2,2)

how do i work that out 😭
erm
you should paramterise first
y²=4ax
as
(at²,2at) for all real t
but i think it might not be
pertinent for you
yea we havent even been taught this concept
i think imma move onto other practice questions
thanks alot btw
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Hi i need help with this
<@&286206848099549185>
@uneven thistle Has your question been resolved?
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Hi y'all, I'm super stuck on this problem and was hoping someone could give me a hand:
Let ( I ) be an ideal in a commutative unital ring ( R ). Define
[
\widetilde{I} := { r \in R \mid r^n \in I \text{ for some } n \in \mathbb{Z}{>0} }.
]
Prove that ( \widetilde{I} ) equals the intersection of all prime ideals of ( R ) which contain ( I ); that is,
[
\widetilde{I} = \bigcap{\substack{P \supseteq I \ P \text{ prime}}} P.
]
theaveragejoe6029
@opaque nova Has your question been resolved?
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Can anyone help me with question 1? (if someone could check my other answers that would be appreciated but i know that it might be alot so i understand if no)
for number 1 you add the elemnt in place a_11 with the element b11 and a12 b12 and so on
So the answer is c. I?
yep but feels weird not writing it as a matrix tbh
xd
Thank you
How do i close this again i forgot
.close ,
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How do I find x and y?
sine rule it or cosine rule it either one will work
I am in 9th grad geometry, we have Not learned that yet 😭
https://www.mathsisfun.com/algebra/sohcahtoa.html this website is very helpful
also has interactives to see the wavey bits :3
at least as far as i remember ill find it
SOHCAHTOA was in our Grade 8 classes.
what country are you in?
what country do you do school
ty
how about we stop comparing grades and just do the problem
https://www.mathsisfun.com/algebra/trigonometry-index.html ii think this is the main one where u can access the wavey bit
Philippines. Although it was at the end of my grade 8. (Before the curriculum change a few years ago.)
if u dont mind, what age is that?
Anyway SOHCAHTOA should solve for the missing side lengths
do you know the law of sines?
https://www.mathsisfun.com/sine-cosine-tangent.html ahah i found the interactive @craggy matrix
same website different page
Oh nice. Never realized this site had stuff like this.
alternatively ,drop a perpendicullar from the vertex including the angle of measure 100, and then find the new angles
Can you close one of your channels
aus schooler, i only remember learning trig in like year 9, year 8 intro was like a single lesson teacher mentioned offhand
^
this is by far the easiest method
can we just focus on the problem please
This if you don't know what garlic suggested
did you work it out?
this is what whatawonderfulworld was saying btw
sohcahtoa is just a formula of ratios that applies to every right angle triangle
i can recommend a nice yt video lol
This video tutorial provides a basic intro into trigonometry. It explains how to evaluate trigonometric functions like sin, cos, and tan using soh cah toa and right triangle trigonometry. It explains how to use reference angles and coterminal angles to evaluate trig functions such as sec, csc, and cot.
Trigonometry - Free Formula Sheet: ...
like this?
i love organic chemistry tutor
yup
@craggy matrix Has your question been resolved?
Quick question, does this affect the original equation, or are they 2 completely different equations?
wdym
Does tje [octire I just sent, affect the 1st picture?
@craggy matrix Has your question been resolved?
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how did the answer pi/9 come to be?
!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.
yep
like my teacher teaches it so its like u simplify the fraction
and so you get 2pi/9
and thats 2 360 rotations which means the coordinate stays in place
but pi/9 isnt a value on the unit circle which ig is why im confused
$\pi = 180^{\circ}$
@autumn girder
oh mb 2pi on the unit circle is 1: 360 degree rotation
Yep
but that means the coordinate still stays in palce
Yes
so does that mean any value that isn't on the unit circle is the reference angle? like im js confused as to why the answer is pi/9 because pi/9 isnt a value on the unit circle
It isn't a value that you've learned, it is (most definitely so) on the unit circle
pi/9?
yeah but only if the value is a value on the unit circle, but like i am pretty sure that it isnt
at least to the degree that we are learning
conversion between radians and degrees is just like any other unit conversion
It is there, it's not a value you've learned though
pi radians = 180 degrees
it does not need to be any special number
any more than a conversion from inches into feet would need to be any special number
Yea we just use this relation to convert
$\pi rd = 180^{\circ} \implies \frac{\pi}{9}rd = \left(\frac{180}{9}\right)^{\circ}$
@autumn girder
or in other terms, unitary method
with all due respect if you know how to work with fractions then you know how to convert pi/9 radians into degrees
okay yeah i think i was js confused as to why we had pi/9
you just have to get out of that "syllabus" mindset if you truly want to learn, and most of the time it probably DOES tie in with your curriculum
Because that's what the author put in question
okay great thanks
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Can anyone check my answer on these questions? If its too much you can do as much as you can and i can just come back later thank you (i know the first one is correct because of someone who helped me here)
2 is right as is 3,4
Thank you
I swear i want to ask the same question
anyway your answer is correct
I dont even know what the fuck that is
for 1
Thanks
Just 5 to 10 left I'll come back later if you guys are too busy
just checked they all look correct
this is so funny to me
but anyways @dusky apex
good job
Thank you
Lol
Thanks
!done
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Ill close now
<3
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Let ( B = {v + w; (-1, 1, 1); (1, 2, -4)} ) and ( B' = {2v; w; (1, 0, 1)} ) be bases of (\mathbb{R}^3).
Find ( v, w ) and ( u ) in (\mathbb{R}^3) such that:
\begin{itemize}
\item The coordinates of the vector ((0, 0, -4)) in the basis ( B' ) are ((1, 2, -4)).
\item The coordinates of the vector ( u ) in both bases are ((1, 1, 1)).
\end{itemize}
938c2cc0dcc05f2b68c4287040cfcf71
(0,0,-4) = 2v + 2w - 4(1,0,1)
(0,0,-4) = 2v + 2w + (-4,0,-4)
(0,0,-4) - (-4,0,-4) = 2v + 2w
(4,0,0) = 2v + 2w
(2,0,0) = v + w
Can someone help me with this question
|x - 2| ^ (log_2(x ^ 3) - 3 * log_x(4)) = (x - 2) ^ 3 , then the sum of values of x ≥3 are
u = v + w + (-1,1,1) + (1,2,-4)
u = (2,0,0) + (-1,1,1) + (1,2,-4)
u = (2,3,-3)
(2,3,-3) = 2v + w + (1,0,1)
(2,3,-3) - (1,0,1) = 2v + w
(1,3,-4) = 2v + w
(1,3,-4) - 2v = w
w = (2,0,0) - v
(1,3,-4) - 2v = (2,0,0) - v
(1,3,-4) - (2,0,0) = v
v = (-1,3,-4)
(2,0,0) = (-1,3,-4) + w
(2,0,0) - (-1,3,-4) = w
(3,-3,4) = w
.close
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finite set are always closed
ohh i got the reasoning now
{0} is finite set and our supreme set is complex set
so compliment of closed set is open
thanks
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"everywhere I have a positive, i will have a negative"
"everywhere i have a negative, i will have a positive"
what does my lecturer mean?
Do you know about mod?
Using the absolute value function takes the positive value for any given x. For instance, if we have $x\in (-\infty,0]$ then the absolute value sign will give us -x (so we get a positive instead of a negative). When we have $x\in [0, \infty)$ we will get a +x (to retain positive. So I guess what your prof is sayin is that if you take a positive absolute value you will always get a positive number, and if you use a negative absolute value you will always get a negative number. (Obviously 0 is neither so it is a common point).
PSCell
$y=\abs{x}\geq 0$ so wouldn't it make sense for $y=-\abs{x}\leq 0$?
parabolicinsanity
but the absolute value "operator"
is
dependant on what input you have
$x\in R^- \implies \abs{x}=-x$ and $x\in R^+ \implies \abs{x}=x$ and erm $\abs{0}=0$
parabolicinsanity
@keen sundial Has your question been resolved?
sorry let me have a read
modulus?
but -|x| is smaller than 0
beccause it will be a negative number unless x itself is a negative
@keen sundial Has your question been resolved?
@keen sundial Has your question been resolved?
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lyzyno
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You're trying to find the maximum value of f ?
Yes
Yo I haven't solved properly
But isn't C and D logically
Wrong
Cuz 2 is not in the domain of f(x)
Or f'(x) assuming the function is differentiable
Yeah that was a trick option
Apparently
@urban otter Has your question been resolved?
Yes
@urban otter Has your question been resolved?
yeah question is weird imo, from the way the function is defined f(2) is out of it’s domain, and for option D to make sense f must be differentiable, not only continuous
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How do I do 9
I feel like its wierdly written
Yeah
what’s the first step?
I'd identify where x and y belong first
How so?
you could start by making a drawing to understand what the text is talking about, it's always a good idea to have a picture in mind
and have you learned green's theorem?
This isn’t a greens theorem problem
I did
do you understand over what you are integrating?
how are you parametrising it?
I thought this was exercise 9?
sorry but I'm confused by the wording of the exercise, they say area but tell you the equations of 2 surfaces
they probably mean the intersection of x+y+z=1 with x²+y² ≤ 1
Yes they do
as such (x,y) move in a circle, z is just the height z = 1-x-y of the plane, probably better not to use it as a parameter
you parametrise the surface and use the formula for the area
have you written down everything?
Yeah
what are you stuck with?
have you tried calculating it?
Yes how do I
there's a procedure to compute it, do you know it?
can you show your work?
I did
There’s no work to show
I can’t cross it with anything
I can’t take the gradient
And I can’t do explicitly
if you take the surface as the graph of the function z = f(x,y) = 1-x-y over the circle x²+y² ≤ 1 you can use the expression √(1 + |∇f|²) dxdy
which is the 2nd you've written
@unborn atlas Has your question been resolved?
How do you integrate that
Did you calculate it?
@nathan
This seems like an exact equation
@unborn atlas
And you probably have to integrate the function along the square
Its not exercise 9
It's 11
Oh it's not?
They miswrote the number
Ohh sorry
Surface integrals huh?
Reminds me of greens theorem
I will look into greens theorem tomorrow
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Given that
\begin{align*}
\cos x + \cos y + \cos z &= 0, \
\sin x + \sin y + \sin z &= 0,
\end{align*}find
\begin{align*}
&\tan^2 x + \tan^2 y + \tan^2 z - (\tan^2 x \tan^2 y + \tan^2 x \tan^2 z + \tan^2 y \tan^2 z) \
&\quad - 3 \tan^2 x \tan^2 y \tan^2 z.
\end{align*}(Assume $\cos x,$ $\cos y,$ and $\cos z$ are all non-zero, so $\tan x,$ $\tan y,$ and $\tan z$ are all defined.)
Dork9399
from the two equations i got
$e^{ix} + e^{-ix} + e^{iy} + e^{-iy} + e^{iz} + e^{-iz} = 0 \ e^{ix} - e^{-ix} + e^{iy} - e^{-iy} + e^{iz} - e^{-iz} = 0$
Dork9399
The find seems to have some simplification
Dork9399
(e^{ix}+e^{iy}+e^{iz}=(\cos(x)+\cos(y)+\cos(z))+i(\sin(x)+\sin(y)+\sin(z))=0+0i=0) (by Euler's formula)
without loss of generality assume (x=\theta,y=\theta+\frac{2\pi}{3},z=\theta+\frac{4\pi}{3})
PajamaMamaLlama
just an idea ¯_(ツ)_/¯
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say i have a function e.g f(x)=5cos2x-1 for the range of a one to one function from 0<x<pi/2. how would i deal with the cos2x when trying to get the inverse of the function. so far i am at (y+1)/5=cos(2x)
and then i would also want to find the new domain and image set/range for this new inverse function
is it just 1/2arccos(_) bc it feels wrong to do that
f and f^-1, you will have Im(f) = Domain(f^-1) and domain(f) = Im(f^-1)
if you have no domain issues it's completely correct to do that
The thing is that you have 2x between 0 and pi so there is no real problem to this since arccos(cos(x)) = x for x in 0,pi
so when solving a normal equation with cos 2x and i try to divide by it it just always go to arccos
and would it go to 1/2arccos
Here yes
and is arcos the same as cos^-1
wdym exactly? 🤔
in general for inverting a trig function, if the domain doesnt match the usual one
to some cos(2x)=something we take arccos then 1/2 it to solve for x
you need to define a customized inverse, and say, like
chartbit!
"here cos‐¹(y) is defined as y=cos x for x in blah, y in blah"
if regular arccos doesnt work
ok so i am fine doing what i have done
and then i just gotta try get my head around the domain and image set when its inversed
can i work through an example of a function i make up as helps if i work through it and make sure im doing it right
so f(x)=2cos(2x) domain: 0<x<pi/2 range: -2<y<2
inverse of that would be:
y/2=cos(2x)
1/2arccos(y/2)=x
f(x) inverse = 1/2arccos(x/2)
inverse domain: -2<x<2 inverse range: 0<y<pi/2
is that correct?
yes
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thanks guyss
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am i right with A here
Alex
same
Oh wait
okay ill go with this
I'm wrong
oh shoot okay
only A and B have (r,theta) = (4,0), and only A has (r,theta) = (-4,pi/2), so it's A
i got it i understand
just submitted
was right
i suck at polar though
the AP Calc BC test was today and it was on an FRQ and I probably didn't get many points on it
man ik thats stressful
prayin u pass man
I feel pretty good about everything else though
Haha I think I'm gonna pass I just want a 4 or 5 so I get credit for Calculus 2
Yea I'm a junior
can you not do calc next year?
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it looks easy for me but I just don't get the logic behind it, can someone help?
you can try to think of it as when do you have a max of |f(theta)| on 0 < theta < pi in terms of absolute value because radius is not negative
notice that since f(theta) < 0 you actually have (f(theta),theta) = (-f(theta),theta+pi)
oh i didnt see that
wait, if that function is a circle, doesnt that mean that all points are spread out equally from the center?
so that would rule out a and b
yes, however the center here is not the origin, and when it comes to distance we are interested for distance from a point to origin
and the argument here is, that the maximum deflection of f(theta) in absolute value occurs at x = pi/2
ah i get it
i graphed out the 2 functions, is this supposed to be a correct representation?
the blue one, yes
ok
the circle is flipped because remember when i said for all points, when r < 0 then (r,theta) = (-r,theta+pi) so to make r positive
yes
and that therefore is the farthest
yes
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Let $a$ and $b$ be integers , not both zero. denote $d$ as the generator/the smallest element of of the subgroup $\Z d = \Z a +\Z b$. Prove:
\begin{enumerate}
\item d divides a and b
\item if an integer $e$ divides $a$ and $b$ it also divides $d$.
\item There are integers $r$ and $s$ such that $d=ra+sb$
\end{enumerate}
Define $S= \Z a+\Z b ={n \in \Z \mid n= ra+sb}$
\~\
\begin{enumerate}
\item As $a \in \Z a$ and $0 \in \Z b$, it follows $\exists k \in \Z$ such that $k_1d = a \implies d \mid a$. Similarly as $b \in \Z b$ and $0 \in \Z a, \exists k_2 \in \Z$ , such that $k_2d =b$. so $ d \mid b$. Therefore $d$ divides $a$ and $b$.
\item As $a \mid e$ and $b \mid e$, it follows that it belongs to $\Z a$ or $\Z b$. Thus It belongs to $\Z d$ too( By definition). Therefore $d \mid e$
\item $\textbf { This is essentially asking me to prove bezout's lemma, right ?}$
\end{enumerate}
What a wonderful world !
- messed up the definition of k
- looks good
- yes
Hmm, should be k_1,k_2, right
yes
tbh i dont think you have to prove it actually, but apply it
I can just say the previous two together define $d$ to be the $GCD$ of $a,b$ and thus by bezouts this follows?
What a wonderful world !
yes, also 2. could be more thorough
and you wanted to say e | d
yea
Can I close this now, then?
sure
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im jus curious
what you do
cry usually
a lot of them work in defense, finance, software jobs, actuaries etc
If you're very good, unis
worst of all possible worlds is teaching
Best for some
academia low-key sucks
Teaching + research
i realized that this semester
don’t want that
looks horrendous
poor compensation for some of the hardest work there is
It is fun, yes. But very challenging too
i see
Most of us will maybe prove one major result in our life, and that;s a huge maybe
no
after years of work
if you're a math major and don't have a minor or anything, finding a job is gonna be really hard... speaking from experience
gotta have some sorta secondary focus
are you american
unless you're teaching i guess
I'm going to minor in sociology, let's see where that takes me ( Another mostly academic field)
that sounds tuff
that sounds pretty random lol, know what you're gonna do?
it seems like all of the "math jobs" like defense, finance etc look for phds
I've done one course ( Anthroplogical thoery), really enjoyed it and got a B ( 8 grade points), so going to do it just for fun
and a phd is just such a resource sink
takes like fucking 6 years
horrible pay
are you in engineering?
yea
mech
whats the highest math
id have to take
?
yea like reading through rudin really made me question what i’m even doing
oka
Probably differential equations, maybe basic Tensor alegbra ( I think it's used in mechanical )
if you're doing engineering bachelor's, the highest you'd do is probably differential equations or multivariable calc
yea , a little "Complex analysis " maybe
most engineering schools offer comprehensive courses that cover the random math topics like complex analysis
@storm raptor probably knows better( They're doing engineering + math)
fourier series too
what about acturial though
this doesn’t
i’m taking my actuary exams this summer
good luck!!
i dont even know what a ctuary exma is but
it sounds like
high intellectual stuff
pretty much 😭
I'm in actuarial science, it's a good field. you need to take a lot of extra exams (outside of school) to become one
which exams did you take
oh
I've passed P and FM, taking SRM in 2 weeks
nice thing about that field is if you pass more exams, you automatically get a raise
so if you like taking tests and you like math, that's the way to go lol
uhhh base pay is almost always at least 70k, depends on how many exams you have
photomath dying out before i got good enough at math is something i will always be pissed about
my brother did photomath duing covid and it was actually really convenient
That's pay I'd die for tbh
70k is enough to live a lavish lifestyle here
it’s like poverty line in some american places lmao
yeah really depends lol
it's upper class in other parts of the world 
but highly recommend if you don't hate stats and probability
is it even worth taking graduate pure math classes
like i can load up in the next few years
get into graduate courses
but what’s the point
for fun :p but no technical reason to if you're not going into a graduate program
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oops had to delete because the image wasn't that good
there are only 4 ways such that tulip and rose always together
and total number of wways = 6!
6!-4*4!*2 seems to make sense to me
4! ways of arranging other flowers, and 2 for arranging the rose and tulip
Sorry, i meant to write R instead of S on the other cases
alright
Yeah I think you're right
see this
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How do you find period on sin graph
Yes
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could I have this proof reviewed? 
#1368757937954099342 message
This works I think. I had a harder time reading the bit about M_1 not being embedded though
I think it works, just the bit about that not being embedded is stinky
hmm, do you have any suggestions?
Well you say U isn’t homeo to an open subset of R^2, but it’s a 1d manifold so that wasn’t the goal?
And you can remove a point and make the line {y=0} disconnected
So I don’t think the argument about not being embedded quite works
Plot M_1 fr
Art suggested something with connectivity and/or connected components
so I'm trying to use that
it's a self-intersecting curve
Yeye, there’s points that removing would disconnect but also points that wouldn’t
Which is not very good
hmm
can I argue via number of connected components? 
like deleting (1, 0) gives me 4 connected components if I choose U small enough
and it was homeo to an open subset of R, it should only disconnect into 2 components
Ye it turns from 1 into 4 pieces for all small enough neighborhoods
And that doesn’t happen in R
But that means M_1 can’t be an immersed manifold I think?
Since it’s not a manifold at all?
Certainly the image of an immersion you gave, I think, but it’s not a manifold
immersed submanifolds need not be topological manifolds
I was just complaining about this in #math-discussion an hour ago 
Well it’s the image of the immersion of the thing you gave but what’s exact conditions to be an immersed manifold
because the topology on an immersed submanifold needn't be the subspace topology
The immersion kinda thing isn’t an injection at all right?
Might be on each component of the domain, but the two parts both hit the intersection?
subset of a manifold endowed with a topology and smooth structure st the inclusion is a smooth immersion, but the topology doesn't have to be the subspace topology
the important thing though is that Lee has a propsition where he says that the images of injective smooth immersions are immersed submanifolds
in my case, M_1 should be the image of G which is smooth and injective and has nowhere vanishing Jacobian
so immersed via the prop
this thing
Is G injective tho
why wouldn't it be
Doesn’t it hit the self intersecting point twice?
no
I deliberately excluded -1 from the domain so that it doesn't
it hits that point at t = -1 and t = 1
if no more -1, then nothing to worry about 
and its image is still M_1
Certainly not a connected domain, which idk if you require that
idt Lee's prop minds that
But if excluding that makes you injective then yeah sure
In this topology, it thinks it’s disconnected though I think
I mean, does it matter if M_1 is disconnected, if it's not gonna be a submanifold anyways? 
True

alright, I'll go write that argument about connected components a bit better
Yeyeye
but why are they not necessarily manifolds grr
anyhow, tanq Sharp 
.solved
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I'm not sure where did I make a mistake
@dry leaf Has your question been resolved?
<@&286206848099549185>
Hello ┬─┬ノ( º _ ºノ)
<@&286206848099549185>
Please somebody help I'm getting stuck every time I solve this way
@dry leaf Has your question been resolved?
@dry leaf Has your question been resolved?
<@&286206848099549185> please help
Yes, but my answer is wrong
Huh
Let's call acceleration of m3 a
What's acceleration of m1 and m2 in terms of a
I need to know what's the mistake in my solution because I already have answers like these
Ok I can't really understand ur solution
I've isolated the m2 and m3 pully , so they weigh 5g
And we've got tension 2T
And a1 should be equal to that which is produced by the net force
on that isolated system
Can u show me a diagram marking all the tensions and acceleration?
I've that in the second image
you did the same mistake in all the equations if it was that way
m1=1 so that is what I've written
I don't see a clear relatiom between accelerations
5g - 2T = 5a1
If u could answer my questions it would make this a lot easier
The thing is that I already have the answers that way, with using pseudo force, relations, etc
Pseudo force???
U only use that when the reference frame is accelerated
Why would u use that here
Yeah, the second pulley will experience pseudo force when we calculate it in its own frame
💀 alr then I guess wait for someone else to help...I can't work with this method
I'm not using pseudo force if you understood that
anyways
like I said
i still have a slight feeling that you messed up the second law somewhere
like this one
and why is 2T = 5g
I don't know, nor I've written that exactly
It's when you know a1 =0
I just need to know where's the mistake
a1=0??
then the mistake is when you assumed 2T = 5g 😂
Is that the correct answer?
Where do you see that written this way exactly
Nope
because you just replaced 2T with 5g..
Dude this is not how u solve pulley questions 😭
5g - 2T = a1
5g - 5g = a1
a1 = 0
Because you see I have calculated the value of T and 2T is 5g
But what's wrong is what I want to know because if you don't write any false statements in science then you can't have a false result
pretty sure it should be 3g - T = 3a3
Can you pinpoint where I've written this
See carefully there's a division by 3
this one?
Yeah my bad but still won't get the answer
Yes this is from hc verma book
I've solved this many times in the past after looking at the solutions 😂 but my natural approach always gets me stuck
And I want to correct the mistake in my natural approach
Same, btw I must ask how the lower pulley moves from rest even after zero force
well
im getting the answer using constraint relations
now to see for isolated systemss
acceleration can be anything
but net force should be zero
And how's the acceleration produced
Yes
spooky wizard magic
we can't really say until it's constrained
the physics we are using now is mere speculation to understand
whats going on
Uhh someone let me in too?
no one's blocking
the op says they can't get the answer using their natural thought flow
It's a lot to read🥲
and is asking why they can't take the two lower blocks as an isolated system and add another equation
Okk I'll need to read the whole thing
im getting an equation with 5g - 2T on the LHS after using pseudo force and simplifying in terms of relative accelerations
Wait wait wait
One thing
How is he equating t on LHS and a on rhs??
Force and acceleration mustnt be equated like that
Or am I missing something?
they arent
So my call is the whole thing is wrong?
and now the op just wants to know if the isolated system method will actually work
Isolated system?
If u talk about the bottom pulley it's never isolated
Coz it has a force being acted upon by thee upper pulley
yeah
but it sounds like an interesting idea
If u balance the force and then think about it, you can call it isolated
But I must say it's all meaningless discussion until the equations are correct
Yes you are missing a mistake
What am I missing?