#help-39
1 messages · Page 328 of 1
Yeah makes sense, but not rn, I am prepping to do the Aleks so be ready to see me again lol
if youre done, you may close the channel with .close
Closed by @pastel valley
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Can someone explain what intuitionism is and how it's different from formalism
In philosophy of mathematics, intuitionism, or neointuitionism (opposed to preintuitionism), is an approach where mathematics is considered to be purely the result of the constructive mental activity of humans rather than the discovery of fundamental principles claimed to exist in an objective reality. That is, logic and mathematics are not cons...
So is it just constructivism
In the philosophy of mathematics, formalism is the view that holds that statements of mathematics and logic can be considered to be statements about the consequences of the manipulation of strings (alphanumeric sequences of symbols, usually as equations) using established manipulation rules. A central idea of formalism "is that mathematics is no...
What are you confused about?
Like is it just about not accepting the law of excluded middle
Like if you try to outline the details of differences between formalism and intuitionism
Because rules of inference exist in both schools of thought right?
<@&286206848099549185>
intuistionistic logic rejects both (axiomatic) lem and double negation elimination
Isn't that the same thing
not that i know of
Huh
i think theres a different definition of negation
Double negation elimination aka "if it ain't not false, it must be false" just is a restatement of lem
Oh?
It is the same
You can formulate classical logic using either, they are equivalent
So like my question remains
unfortunately I'm not a philosopher so I can't help you much here
Just ask ChatGPT
!noai
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
actually, this may be a good question for #foundations?
Not for mathematical tasks, but ok for the philosophy of mathematics
!no
Please never suggest use of LLMs to anyone, and definitely not in help channels
If that were so, OP wouldn't have taken the pain to open a help channel
Have you asked your professor, or your teacher, OP?
Intuitionism is like a constructive creation of the human mind instead of relying on existed truth.
I'm just studying on my own
Formalism is considered to be the field using symbols strictly, rather than relying on existed truth.
How nice.
is there anyone who can help me out with statistics, i need to study for a test i have tomorrow which will make or break whether i can come back to the school im at next year so I'm really stressed right now
!occupied, please open an available channel like #help-21|아리스킨충1.
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #❓how-to-get-help for instructions).
Yeah I saw this, but this seems empty to me, like what does that mean, like why can't formalism be regarded as a constructive creation of human mind?
got confused
I too know very little about this, but I don't think that you can reduce those views just to the axioms / rules of inference they accept / don't accept. They are much more broad than that. They also view mathematics as a whole differently, and "mathematical truth" has different meanings in them.
To me, intuionism is the view that mathematics is a mental construct of individuals rather than some objective stuff. Truth then corresponds to being able to make a constructive proof, and falsity means being able to refute it. From this view, it pretty much follows that LEM, double negation and contradiction arent valid proof techniques. (You cant just say A or not A without proving A or refuting it)
Formalism on the other hand is the view that mathematics is just about manipulating some strings according to some rules. Those strings don't necessarily have inherent meaning, but one can choose to assign meaning to them.
Well I am not specialised in this field much, that's what I have learned so far.
The barriers between them are vaguely pointed out.
Could the foundation channel explain this?
Hmm
Also I had another question
Ask away!
what quantifies the "power" of a certain foundation of mathematics
What do you mean "power" here?
Like the "expressive" power of some axiomatic system? E.g. in the sense of being able to embeed arithmetic in it?
I can see two things
One is how much of what is true with the axioms outlines is provable in the system
And second is how much truth is expressible in the system
Yea one of the things
Like I think not all ZFC proofs are expressible as programs right
In proof theory, ordinal analysis assigns ordinals (often large countable ordinals) to mathematical theories as a measure of their strength.
If theories have the same proof-theoretic ordinal they are often equiconsistent, and if one theory has a larger proof-theoretic ordinal than another it can often prove the consistency of the second theory....
this could be relevant (but i know practically nothing about it, i only heard about it when i did logic)
Dude I try to learn one thing (1) and now I have 89 wiki tabs open and have learnt nothing

I started out trying to learn STLC
Anyway thanks for yalls help!
I'll have to sit and ponder more

Thanks! @autumn fossil @wicked edge

.close
Closed by @junior anchor
Use .reopen if this was a mistake.
How are you going to know which tabs to find then?
Wrong reply ;-;.
I will have to keep notes
I am trying to create a graph of how one concept connects to another
I usually don't take notes
Interesting.
So I often end up doing some mumbo jumbo


Well, if you want a simpler but not so complete answer, then you could just claim that a system A is weaker than system B, if you can embeed A in B (for the expressiveness)
For the proof power, (which i think can be reasonably compared only in systems with similaar expressive power) system A is weaker than system B, if everything provable in A is provable in B
those "weakers" are not strict btw, and it only orders them partially, not totally
which, i guess, is to be expected
Yeah, 




Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi guys!!! I need help with the last part of this question (ii, b). I feel like im missing a bit of knowledge on what to do.
do you get how matrices relate to linear transformations
You multiply coordinates by the matrices to get the transformed points
yes
what is the matrix for rotating twice
so rotate by theta once
then rotate by theta again
so do B twice
the matrix is B^2
Let me see
in general, you multiply matrices X and Y to get XY, which represents do Y first then X
this is a new linear transformation whose matrix is the product XY
so composition of functions corresponds to matrix multiplication
Kk
Why is n 3
wait i'm getting there
Kk thx
The original position?
Oop sorry
Oh the reflection?
yes, 180 degrees
Kk
if you rotate something by 30 degrees then 30 degrees again, what do you get
60
yes
Kkkkk
so B^2 is rotating by 2*theta
Ohhh ok
Makes sensee
what did you get for ii.a
240
240 n is equal to identity
mhm
backwards?
Knowing the answer. How do I know that it is 720
If that makes sense😭
you check each n one by one
if n=1 implies 240n=240, not the identity
what if n=2?
no transformation
identity matrix
1 along main diagonal 0 everywhere else
Ye, tis might seem stupid but I js took that as 1
Like
240n = 1
I don't know 😭
what happens if you rotate by 360
Sorry yall✌️✌️
Tye points come back to the original position?
Oh I see
LHH MK
I get it 😭
I difnt see the integer part mb
Tyy
Sorry for thetrouble lolz kk
.close
Closed by @placid steppe
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I am confused cuz i just learnt intregration with u sub and with parts
Now i am trying to learn integration with trigonometric sub
And im confused tbh
i know that if it is sqrt a2 - x2 it is x = asin
sqrt a2 + x2, x = atan
sqrt x2 - a2, x = asec
but im stuck at thsi question tbh
well, which of these that you listed fits into this question?
Well non of them, no? because the requirment of sqrt() isn't there?
it is one of those 3, promise
Im confused isnt sqrt supposed to be one of the req for the x to be 1 of them?
but if sqrt is not, then its the 2nd one
the atan
be careful tho x^2 has a coeffiicient!
true
yes
it becomes 2^2 + (sqrt(3)x)^2
Try putting x=2/√3 (sin theta) you will get 4 cos^theta in denominator. Maybe that help a little bit
What?
I did this for atan
then would i just do 4 + 2tanTheta?
or am i missing smth
The question asked for the suitable trigonometric substitution. I may be not correct but maybe that substitution can help u out
im so confused icel to you, cuz idek what trigo stuff i have to memroise all i know is those 3 cases?
everything else im actually so confused on
yeah exactly im confused....
you can take the three out!
as in, pull out three from the denominator
that would give you the form you desire,
a^2 + x^2
Break 4 into 1 + 3
well divide the numerator and denominator both by 3
ye but that would make the 4 inton 4/3
isnt that worse?
okay sure
nope!
all we need is this form.
ok 1sec also while we are here what formulas / trig idneities / trig tuff i need to memroise for trig sub, i know those 3 cases but what else?
doesnt matter what "a"becomes
there is list for sin-1 (x), cos-1(x), tan-1(x), sec-1,csc-1, and some logarithm ones
I got 1/(4/3 + (4/3 * tantheta)^2)
basically the major ones you need to memorise are
1/(a^2 +- x^2)
1/sqrt(a^2 +- x^2)
1/sqrt(x^2 -a^2)
sqrt(a^2 +- x^2)
sqrt(x^2 - a^2)
+-??
man, if only there was an easy way to do this (the sweet and humble triangle)
-# which country or grade btw
Ireland 1st yr
im doing cs major but i have to take 2 math modules
2nd module is easiest thing
1st one is pain
cuz i hate trigo
Anything with trigs is just bs for me
oh sorry then i dont know much
1st yr uh uni
well too bad so we will now be talking about triangles if you don't want to memorize the identities and stuff(depends on what u want)
but you are missing smth
isn't 1/(a^2-x^2) partial fraction-able
ye but still "formula" makes it faster
converts into ln
check you dx!!
estimating area using left endpoint approximation, anti-derivatives, the fundamental theorem of
calculus, indefinite and definite integrals, u-substitution, integration by parts, trigonometric
substitution, partial fractions, applications of integral (length of curve, area under/between curves(s),
volume of revolution using both disk/washer and shell methods), numerical integration.
this is the topics i have
for this module
yes but there's also the key identity that:
[\frac{d}{dx}\left[\frac{\operatorname{arctanh}\left(\frac{x}{a}\right)}{a}\right]=\frac{1}{a^2-x^2}]
im just stuck at stupid trig
Stumpman
teach a man a formula, they can easily forget the formula, teach a man to derive the formula, they can remember for a lifetime
mhmm okay lets first do this qsn
is this the rip off of give a man a fish 😭😭
yes
lmao
😭
@sinful jasper
it works tho
..
ye
so x = 4/3 * tantheta
Wait what is even the derivative of tan? uh is that smth i gotta memroise cuz they only give us this in the exam 1 sec
nvm i mgith be trippin
tan is sec^2?
2/√3 tan theta
You are welcome
Wtf
xDDD
Can't believe people are still falling for this trap
anyway did you sub out dx?
,rotate
,rotate
almost there...
4/3?
Omg
16/9?
.
this was correct no?
no
4/3 should be outside ()^2
2/sqrt(3)
..... okay now im confused
cuz i was told that was correct
wait
4 + 3x ^2
now
dvided by 3
it isnt
okay
so 4/3 + x^2
nice
now compare it with
bro😭😭
what
sqrt of (4/3)
= sqrt(4) / sqrt(3)
sqrt 4/3
2/sqrt(3)
there
yup
okay okay we getting somehwere 1 sec
let me write in my notes rq#
so then
its x = 2/sqrt3 * tantheta
and x^2 is 4/3* tan^2 theta
so its 1/(4/3 + 4/3*tan62 theta)
and i dont know the trig identity but it defo loosk like 1 so we take out the 4/3
so its this 1 sec
Oh wait the dx as well
Are you really in uni?
still stuck?
sorry for disturbing, did you know $1 + tan^2 x = sec^2 x$
夜靈
.
U are on the right track. Keep solving
okay good!!
now you can use this!!
Now I know the bottom bit is an identity, ite just i never bothered to memorise identities, so I needa memorise wm now, do tou mind sending me a list rhar is essential for trig sub
am in 11th rn so may not be sufficient for your level
Would be better to ask uni student
#math-discussion btw
Where r u? USA?
ind🥀
the essential ones are the 1+trig^2 or 1-trig^2
because of the way trig sub works you’ll almost always be subbing in those situations
tan^2 +1=sec^2
sec^2 -1 = tan^2
So the pythag identities?
well for any situation involving trig imo it’s best to also know the half angle identities so you can reduce the power of like a lone sin^2 or cos^2
$\sin^2{x}=\frac{1-\cos{2x}}{2}$
$\cos^2{x}=\frac{1+\cos{2x}}{2}$
dgtdx
these have other variations ofc but you can derive them all basically
😭
Im cooked
Anyways ler me solve the question 1 sec
huh?
$sqrt(3/2 * theta + C$
🥀 repenting_slave 🥀
bro istg
your latex needs a lot of work lol
ik sob
thank god 😭
...
,w integrate 3/(4+3x^2)
i havent finished it fully
why is there a 6 in the denom
cuz that is what i am about to ask
wait why did you do trig sub for this anyway
??
look at the top
the sec^2 cancel
what is left is
1/(4/3) * 2/sqrt(3)
should be 2 in denom man
What
6/4*sqrt(3) is sqrt(30/2
I thought thats a six
could have been solved directly just with antiderivative of 1/(1+x^2)
trig sub not necessary here
okay and how do you do that
you do this using trigo sub
i just plucked 6/4sqrt(3) in calc which gave sqrt(3)/2
this is entirely unnecessary to do though
cuz thats how its simplified
yeah no its correct go on i misread
okay lmk ur method then
in #math-discussion tho
Anyhow now what i was told is cuz it's converted to theta, we gotta get i back to X
and idk how to do that part
so we can just rewrite as x/a = tan theta
then take tan-1 on both sides
-# these come from trigo subs
again
this is a formula that you can use
to skip that step
Bro read the qsn
it clearly says
use trigo sub
and show the steps
what are you on
also lets avoid spamming here
@sinful jasper
yeah no im good
x = atan theta?
so uh
1 sec
let me see
yeah isnt tht the sub we used org?
take your time no hurry!!
that is correct
ye i just dont get how to convert it, we used that sub but where did u get that tan -1 would help..
see,
i saw tan on one side
and this should click that if we have any trigo(theta) = c
we can simply inverse the trigo-1
there are some conditions but since we had org subbed in the values asw its all good
Or inverse tan.
But it just a convention, not a big deal.
I will do 1 more question from it then I will move on to the next topic
Partial functions, dont even know how does a question like that look but I will use rhe chemistry tutor guy ig and see if I undersrand him
okey!!
@sinful jasper Has your question been resolved?
Its a bit messy
no i understand
Ik I should have subbed in properly like did it step by step but once I know the method I usually just skip steps
5sectheta tan theta . dtheta = dx
Now I can first like take out rhe sqrt
Then uh
1 sec
I can make the second half it the denom to be 5(sec - 1)
Not inverse but actually-1
And then I can replace it with tan2
@smoky gull is it just converted back now?
oh sorry
wait
what happened to the sqrt in denom
it should have become 5tan theta??
sec^2 theta -1 = tan^2 tehta
no i am stupid
i forgot its 25sec2theta - 25
idk how i thought i could remove sqrt that
💀
blud cancelled 's' in sinx/cosx type shi
CAP
you are dreaming
Stop lying!!!!!
I got ton 10/625sec^3(theta)
Omg im.stupid
I forgot the 24
25*
Okay forget about the 5, cuz I can divide the 10 by 5 which leaves 2 at the top and 625 at bottom
how did you rven get sec^3 in denom
well in the sqrt we had
25sec2 - 25
so 25(sec^2 - 1)
oh right mb
which is tan2
which turns into 5tan
and the 5 goes with the 10 at the top
so its 2 at the top
and tan with tan and 1 sec with the sec at top
is my workings correct so fR?
yeah here
mb
Wait now im kinda of confused cuz now
i have theta = sec-1(x/5)
so do i make it sec^3(sec-1(x/5))???
😭
you cant sub it back in yrt
okay
you havent performed your integration
@sinful jasper you sure ur qsn is right?
subbing wont save you from integration
you hv to integrate at some point of time no matter how much you sub
yeah
isnt sec like the opposite of tan? idk tbh i forgot or is that cot?
cos..
okay so 1/sec is cos
so oppsoite of sec is cos
opposite of tan is cot
opposite of sin is csc?
ye
can you
here can you simplify the sec into smth better?
so by oppsoite we mean sin = 1/csc and vice verse and for all of em
ye
1/sec3 theta is
cos3
nicee
no
wa
you cant do that right away
first lets rewrite cos^3 theyta into sin^2 theta and cos theta
no
wait what?
😭
that would have worked only when it would have been simply theta^3
here you have to do double substitution ggs🥀
😭
dw ill hekp u out
Oka
So lets
try to recall, cos^2 + sin^2 =1
so cos^2 = 1 - sin^2
now you can see where am going with this kinda
rewriting cos^3 theta as cos theta( cos^2 theta)
subbing, we get
costheta (1-sin^2 theta)
alr 1 sec let me get the rules here
i need to memorise these sob
i think for trig sub thats all i need to memo no?
now, we can assume (1-sin^2 theta) as another var t
mhm prolly for now
try seeing what happens after this
either ways i only got math for this yr and next yr only 1 math module
okay imma sub it 1-sin
1 sec
still a lot of maths
might have to go to ind
to teach me the ways
cuz i never met an indian that is not smart at math
💀
1/1,000,000,000 chance smh
so it becomes
cos(1-sin2)
so its cos - cossin2
yeah im stuck icl to you
ok
so cos()t
so for a var we take it outside?
correct?
,w integrate 3/((x^4)*sqrt(-25+x^2))
gg
@sinful jasper Has your question been resolved?
,w integrate 3/((x^4)sqrt(x^2 -25))
okay im confused
the 3/625 i have outside
insdie the integration we have
cos3
which we said we can chance into
cs2 = 1- sin2
so cos(1-sin2)
souh
cos - sin2cos
we can integrate cos into sin?
but sin2cos?
have you learned u sub
but i can take the cos out and make it intoa sin correct? so it becomes 3sin/625 times intgeral of -sin2cos?
or actually -3sin/625
times integral of sin2cos
I got -sin^4(theta)/625
i have had to do smth wrong xD
Show your full work if you want someone to look at it
it was above but im rdoing the whole question cuz i realsied smth
@smoky gull
I finally get it
Whoever created it trigo, I hope nothing but pain for them
I do finally undersrand them tho so xD
Imma do 1 more than do arlwast 2 more topics
Exam is rhis friday xD
oh damn atb!!
Tyty
Partial functions, applications of integral, area under between curves, volume of revolution using both disk, numerical integration left
Are these easy to learn xD @smoky gull ?
it's not too bad
although sometimes visualizing the graphs can really help when you think about like volumes and stuff
some people have trouble visualizing it but thats all really
partial fractions is pretty simple as long as you dont have some insane power in the denominator
but with simple things like difference of squares it's easy
@sinful jasper Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
well, first of all what is the formula for the sum of the interior angles in any polygon of n sides?
@lean plume ^
(n-2) x 180
yes, so what is your sum?
that's right
.close
Closed by @lean plume
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How is that 3, -1 and 8?
Shoudnt it be -3, 1 and -8?
what are a1, a2, and a3?
The points are written like x-a so x-3 is x-(3) and x+1 is x-(-1)
Variables
yes but they must be coming from a standard formula of some sort
I’ll send the full thing
$\vec{r} = r_{0} + t \vec{v}$
InterGalactic
@desert cliff
Can you go step by step from what we are given im a bit confused
See all the things are equal to each other so let them be equal to the same thing lambda
I gave you a rundown of it in https://discord.com/channels/268882317391429632/903486480075354182
Then write x y z in terms of lamba by that relationship
To get 3 linear equations
Which can just be converted into vector form
Wdym
Like z-8=lambda means z= lamba+8
so your teacher writes
[ \pmat{x \ y \ z} = \pmat{3 \ -1 \ 8} + \lambda \pmat{5 \ 2 \ 1} = \pmat{a_1 \ a_2 \ a_3} + \lambda \pmat{v_1 \ v_2 \ v_3} ]
this is really 3 equations,
[ \begin{cases} x = a_1 + \lambda v_1 \ y = a_2 + \lambda v_2 \ z = a_3 + \lambda v_3 \end{cases} ]
which if we solve for lambda in each of them we get
[ \begin{cases} \lambda = \frac{x - a_1}{v_1} \ \lambda = \frac{y-a_2}{v_2} \ \lambda = \frac{z - a_3}{v_3} \end{cases} ]
in other words
[ \lambda = \frac{x - a_1}{v_1} = \frac{y - a_2}{v_2} = \frac{z - a_3}{v_3} ]
clôud
Yes I understand but isn’t the final part in the Cartesian form
The question said to convert to vector form
well i showed how you would go from vector form to cartesian form
but you go from cartesian to vector form just by recognizing a1, v1, a2 and so on in the cartesian equation
if you don't like that method you can start by setting each of them equal to lambda and then solving for x, y, and z manually
What’s the best shortcut
do you see how the first equation you were given is literally just the last equation here with specific values plugged in for a1, v1, a2, and so on?
Yes
Or you can just say that in x-a1/v1= y-a2/v2 =z-a3/v3 the line goes through (a1,a2,a3) and it's direction ratios are (v1,v2,v3)
so if you recognize those you can just plug them into the first equation here
could you show me the solution or is it the same from the screen?
But I do get the gist of what your saying
that's what the solution seems to have done
Ah I get it
Got it
.close
Closed by @desert cliff
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
from what i understand for a transformation,
it's onto if all vectors have images?
and it's 1 to 1 if for all vectors that have images, each vector maps to their own image?
Onto means that every vector in the target space is mapped to (aka no possible outputs are left out)
One-to-one means that every input vector maps to a unique output (aka no two different input vectors ever share the same image)
so basically for all b's in Ax = b, there's an x for it?
and so i think
Ax = Ay if and only if x = y?
yes
yes
Closed by @fair oasis
Use .reopen if this was a mistake.

Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What is the question asking?
.close
Closed by @desert cliff
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
not sure how to find the maximum possible value here
is it some manipulation? the sqrt(33)(y-5) looks weird
Well, I will just tell you what I think of, don't take into account if this is false.
If I let A = tan x, and given x from -90 to 90, then A must be anywhere from negative to positive infinity.
Then, you can just let the function y, in term of t. So that you can solve quadratically.
Does it make sense @spare rivet ?
@spare rivet Has your question been resolved?
Closed by @spare rivet
Use .reopen if this was a mistake.
No worries.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi I do know this is physics but I don't really have anywhere else to ask for help so I hope someone could help me out
So for the ball question I can use 0.15tan30
Essentially treating the dotted line as the weight to find force of airflow
However why for the rod I can't take the dotted vertical line as the weight and do 400tan37
(I can solve it btw) just unsure why the method doesn't work for 2nd qn
||because the weight of the rod acts about the rod's center, while F acts at point Y. they're not perpendicular components of the same force.
(if I'm not mistaken.)||
ignore this first, and go with Bacter.
what was your idea behind using 0.15tan30 ? Like which physics concept did you use before arriving at this trig expression?
<@&268886789983436800>
they come in waves
I think of it as if there was no air flow the ball would be vertical so 0.15N is also the parallel component then after that I just created a right angle triangle to find force of air flow
yea, the thought is correct, but the actual concept that I am looking for you to name is static equilibrium
so what you wanna do is balance the forces and their moments.
Fortunately for you, the force balance is unnecessary as the tension in the string takes care of that, and calculating that is pointless for the specific problem
so all you wanna do is consider moment balance
Now luckily, as chiaki said, the forces were acting at the same point in your first problem and in the second problem, the forces are acting at two different points
so things worked out even when you directly wrote the expression the way you did
However, since the situation is slightly different in this case, you should start from scratch and first write the moment balance equation and then use that to establish the relationship between the weight and the applied horizontal force
Oh yes the weight acts at the midpoint of the rod but I don't get how it affects why I can't do 400tan37
If there was no F wouldn't thr perpendicular distance from weight to Pivot X just be 0 so it wouldnt matter
Or should I think of taking the weight as the vertical component only works if the force applied is directly on the center of gravity of the weight?
perpendicular distance from weight to Pivot X just be 0.
well, the reason for that is that the rod would be vertically oriented in that case. Application of F changes that, so the distance of the weight vector from the rod is non zero
force of weight always acts vertically (which is the direction of gravity ofc)
and center of gravity is specifically defined to be a singular point where the weight acts as an equivalent singular force vector, so thats not an issue
Oh so the forces have to act at the same point for Me to just take weight as vertical component
Ohh
no, thats wrong interpretation. Forces have to act at the same point, and that itself doesnt change much. However, in special cases it might simplify the expression. Thats all. But you shouldnt bother remembering these special cases. What you should know is how the physics works in a general case, and you should be able to simplify using algebra on the go once you establish the equations.
So in this problem, draw a free body diagram and then moment balance (through the pivot coz that eliminates the moments of the irrelevant reaction forces)
I think in general for any physics problems, drawing an FBD never goes wrong.
Closed by @tough viper
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.

Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how do I calculate the arclength of the equation x^2 = y^3 with -1<=x <=1
Do you know the arclength fomula
So you dont know it
I do know it
but this is not the arclength that I am looking for I think
because the one that I am looking for the is the norm of the parametrization of x^2 = y^3 correct?
Intuitively, it's just Pythagoras, and then you let the hypotenuse shrink very small ds²=dx²+dy²
but you don't have a parameterization
I can make one out of this
ok sure
yeah this is the arclength formula, but I was looking for the arclength formula for a parametrization dawg
@rough forge
not quiet
care to elaborate?
(x,y)
what you have would satisfy x³=y²
||because x=t² => x³=t⁶ and y=t³ => y²=t⁶ => x³=y²||
say (x,y) = (t1, t2)
then t1^3 = t2^2
so t1 = t^3 and t2 = t^2
meaning r(t) = (t^3, t^2)
but thats different from what you stated
also I don't understand your reasoning
say (x,y) = (t1, t2)
then t1^3 = t2^2
where are you confused? @rough forge
you have x²=y³ not x³=y²
what do you recommend then?
you just messed up your exponents
say x^2 = y^3 passes through (1,1) and (4,8)
so we can find the direction vector
(4,8) - (1,1) is the direction
so the direction vector is (3,7) and one of that we pass through is (1,1)
so the equation is
L(t) : (x,y) = k.(3,7) + (1,1)
so (x,y) = (3k + 1, 7k + 1)
so y = f(x) = 7k + 1 with x = 3k + 1 so k = (x-1)/3
basically we get that
y = f(x) = 7/3 * (x-1) + 1
what the helly
You computed the secant line between two points. What does this have to do with your problem? You first need a working parametrization.
Thanks I am speechless
can you guys help or not?
I was just waiting on what you had to say
I am trying to parametrize x^2 = y^3
When you have x²=y³ and choose x=t^a and y=t^b (some powers of t) then you get t^(2a)=t^(3b) or 2a=3b => a=3b/2 so you can choose b=2 for example
this is nonsense, no offense dawg clearly a=b=1
Well clearly not because then x^2 = t^4 and y^3 = t^9. They gave you a systematic way to find a correct parametrization.
i edited
why
Because you're suggesting that (t,t) satisfies t^2 = t^3, which isn't the case.
How can you square one side and cube the other
x=0, x = 1 satisfy
But you want to parametrize the whole curve x^2 = y^3, not two points of it...
If you can't see intuitively what it should be, then this
why do you grab b = 2
but the formula you gave me was for non parametrizable curves
there is an arclength formula for parametrizable curves
look on the right
alright so the integral of the norm of the parametrization
yes
what is alpha what is beta @rough forge
the bounds for t
what are my bounds for t
if -1=<x=<1 then figure t
?
how was x(t) defined in your parameterization
x = t^3
what follows
Well now you have your bounds for the arclength formula, which you've already seen and used before.
What do you need help with?
im still unsure how to join every puzzle piece together @rough forge @summer imp
Yeah it's like everytime is your first time doing math
Look at the formula that was given to you or the one you're using in class. Compute what you need to compute.
It's not any different than the last times you've done it.
I can assure you the definition you're using didn't change since last time.
,, \text{arclength(shit)} = \int_{-1}^1 \norm{\varphi(t)} \ dt = \int_{-1}^1 \sqrt{t^6 + t^4} \ dt
Renato
where $\varphi$ is my parametrization \
Wrong definition.
Renato
This is neither what star gave you as a formula, nor is it the formula you've seen.
You didn't differentiate the components of your param
how so ? @summer imp @rough forge
because the arc length formula requires you to do so
pretty sure the left hand side of the equality is the standard for arclength of a parametrizable curve
correct?
It should be phi'.
what?
When computing the arclength you're integrating the magnitude of the velocity
Not the magnitude of the position.
Renato
@rough forge

What's the velocity vector of your parametrization?
I am not a physicist dawg
...
What's the tangent vector of your param
$\text{tangent vector(\varphi)} = \frac{\varphi '(t)}{\norm{\varphi(t)}}$
your are taking the norm of phi' not phi
Renato
$\text{tangent vector(\varphi)} = \frac{\varphi '(t)}{\norm{\varphi(t)}}$
```Compilation error:```! Missing $ inserted.
<inserted text>
$
l.60 $\text{tangent vector(\varphi)}
= \frac{\varphi '(t)}{\norm{\varphi(t)}}$
I've inserted a begin-math/end-math symbol since I think
you left one out. Proceed, with fingers crossed.```
pretty sure there is no mistake in the latex
but somehow there is a mistake I cant see
i am sure you are missing the bigger picture now
we just want to know what's phi'(t)
@summer imp wdym?
It's fine just ditch the latex. What is phi'(t)?
\text{tangent vector}(\varphi) = \frac{\varphi '(t)}{\norm{\varphi ' (t)}}
What. Is. phi'(t). ?.
is the derivative of the parametrization of the parametrizable curve
I'm not asking for the definition.
You have a parametrization
I want you to write down what phi'(t) is
For that parametrization
In other words: Apply what you already know
yeah
yeah
my parametrization phi(t) is just (t^3, t^2)
so if we differentiate that shit assuming phi is C1 we get that @summer imp @rough forge
3t^2, 2t
What's the magnitude of that?
that magnitude is just sqrt((3t^2)^2 + 4t^2)
thats the norm of my two dimensional vector in R2 @summer imp @rough forge
integrate
What do you mean what about it?
Now you have your integrand, you integrate it to get the arclength.
how do I integrate this shit?
For integration I can give you a hint: ||factorize t² and substitute inside the sqrt||
,, \text{arclength of } \varphi(t) = \int_{-1}^1 \sqrt{3t^2 + 2t} \ dt

