#serious-discussion

1 messages · Page 2 of 1

vocal roost
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then it's multiplied by the derivative of the inner function

wild lantern
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P much

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For ex D(e^(2x))=2e^(2x)

storm sage
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I mean understanding the partial derivative definition is really easy if you understand the regular derivative definition

wild lantern
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Let f(x)=e^x and g(x)=2x

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And recall D(e^x)=e^x.

vocal roost
#

Yeah I don't understand chain rule still

storm sage
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that's okay

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everything takes time

bright locust
vocal roost
#

I dont work with function in a function

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wtf

wild lantern
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Just gotta do some examples until it makes sense

storm sage
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nesy do you know what function composition is

vocal roost
#

yes

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f o g (x) for example

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f(g(x))

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g(x) is basically your input value and it maps to all x in the f(g(x)) function.

storm sage
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yep

vocal roost
#

but 2x is not a composite

storm sage
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anything can be a composition

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of two functions

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sometimes it helps you to view things that way in order to more easily take the derivative

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for example, with e^2x, then you can take f(x) = e^x and g(x) = 2x

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you already know how to take the derivative of f and g

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so you can use the chain rule to take the derivative of f(g(x))

vocal roost
#

so you

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can split the functions up?

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into compositions

storm sage
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yes

vocal roost
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well i need to let this rule marianate in my brain

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because im a bit doubtful that i understand it

finite tusk
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Missing the most beautiful part

vocal roost
#

"the peach can..."

ancient flame
#

...

vocal roost
#

säs

ancient flame
#

I still don't understand what that means

storm sage
#

nesy is the king of poor communication

vocal roost
#

säs is sus

ancient flame
#

so then why say it that way

vocal roost
#

its fun

ancient flame
#

...

storm sage
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I mean

vocal roost
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to do the slighest bit of trolling

storm sage
#

you can say it like that if you want

ancient flame
#

it's a whole different pronunciation

storm sage
#

as long as you tell other people what you mean

vocal roost
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i've done that

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countless times

storm sage
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well

ancient flame
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ur so weird

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lmao

vocal roost
#

yes, now live with it

storm sage
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yeah you should expect to do that since no one knows what it means

vocal roost
storm sage
#

xD

bright locust
vocal roost
#

no

bright locust
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For math’s sake

storm sage
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also wtf ä and u don't sound similar at all LOL

vocal roost
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it doesn't

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it's what I call

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"slightest bit of trolling"

bright locust
ancient flame
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how is that trolling

vocal roost
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i mean you guys... kekw

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come on

storm sage
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All language is nonsense

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Except through interpretation

vocal roost
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I still dont understand why 2x could be a composition.

neat lintel
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2x is composition of 2 with x

vocal roost
vocal roost
ancient flame
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...

vocal roost
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i mean

ancient flame
#

that's your fault

neat lintel
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2*_ is a function that sends x to 2*x

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x is a function from 1 to R or something

ancient flame
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say f(t)=2t and g(x)=x, then f(g(x))=2x

wild lantern
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You can always let f(x)=x and then if you have any other function g(x) you can write g(x)=g(f(x))

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You can always come up with compositions, they just might not be interesting lol

storm sage
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2x can be a composition in an infinite number of ways, it's just not useful if you want to take the derivative of 2x

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since you can already take the derivative of 2x

ionic star
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i think you learn anti derivative of y'=x before derivatives

storm sage
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without expressing it as a composition

vocal roost
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literally not helpful

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to do that yeah

storm sage
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yes

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you are correct there

wild lantern
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It is for derivative of e^(2x)?

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Oh wait nvm

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Lol

vocal roost
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so i need to find some convinient way of using chain rule

ancient flame
#

even just x could be a composition

storm sage
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you only use the chain rule on problems where the chain rule is useful (although you can use it on any derivative problem if you really want)

ancient flame
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let's say f(t)=ln(t) and g(x)=e^x, then f(g(x))=x

storm sage
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it's useful to evaluate the derivative of e^(2x) with the chain rule

vocal roost
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f(x)=e^x
g(x) = 2x

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f(g(x)=e^(2x)

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I dont know how to take the derivatives of e^x

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yet

wild lantern
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Try cos(2x+1) with chain rule. What is a good choice of f(x) and what is a good choice of g(x)?

ancient flame
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$\dv{x}e^x=e^x$

fathom swallowBOT
vocal roost
wild lantern
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Yep

storm sage
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👍

wild lantern
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Then just use the chain rule formula basically.

vocal roost
#

so the derivative of cos(x) wrt x

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was it sin(x)

wild lantern
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Almost

vocal roost
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-sin(x)?

wild lantern
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Yeh

vocal roost
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-sin(x) done

2

-sin(2)

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is the answer

wild lantern
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Nah

vocal roost
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wat

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the derivative of 2x+1 wrt x

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its 2

wild lantern
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There's more to it

vocal roost
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oh right

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the other part of the chain rule

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-sin(2) * 2

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?

wild lantern
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Also the argument to -sine is wrong

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It's (f(g(x))'=f'(g(x))g'(x)

vocal roost
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is it -sin(2) * 2

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tho?

wild lantern
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For the f' part you evaluate it at the original g not the derivative of g

vocal roost
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oh

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the inner function stays intact

wild lantern
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Yep

vocal roost
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wtf, aight

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thats interesting

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-sin(2x+1) * 2

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?

wild lantern
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I kind of imagine it like I'm taking the derivative around the inner function then multiplying by the derivative of the inner function

vocal roost
#

doot

wild lantern
vocal roost
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ye

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So i need to multiply that

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(which i clearly dont know how to do)

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lacking trig

wild lantern
wild lantern
vocal roost
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so you'd allow it to be in this way

wild lantern
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Unless they had a reason to write it another way

vocal roost
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?

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ok

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I guess chain rule is starting to make sense

wild lantern
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You can sit around coming up with other random compositions and using chain rule to compute them

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One really common exercise is telling people to compute stuff like the derivative of a(b(c(d(x)))).

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It gets kinda nasty ofc lol

storm sage
wild lantern
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Yeah yeah lol

bright locust
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That’s what it should be

vocal roost
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well...

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the more i think about it

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the more easier it seems to become in my head

storm sage
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yay!

vocal roost
storm sage
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what do you mean

vocal roost
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derivative of 2xy

storm sage
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but what is y

vocal roost
#

2xy with respect to x

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not partial derivative but derivative

storm sage
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but what is y

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is that a function of x

vocal roost
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a variable

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multiplying 2x

storm sage
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is it a function of x

vocal roost
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f(x,y)=2xy

storm sage
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like y = f(x)

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well right but

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what is y

vocal roost
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wait

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these are multivariables

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ah

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you need partials for that i realised

vocal roost
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because non part derivatives work with terms that have only 1 type of variable

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right?

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like cos(2x^2+2) and etc.

storm sage
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yes

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if y is a function of x then you can take the derivative of 2xy

vocal roost
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but it needs to be partial

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right?

storm sage
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no in that case it's an ordinary derivative

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if y is a function of x

vocal roost
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so the derivative of

f(x,y) = 2xy

storm sage
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no that's a multivariate function

vocal roost
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that's what I ment tho

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if you can take derivatives(non part) of multivariable functions

storm sage
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however if you have f(x) = 2xy where y = some function of x, then you can take the derivative

storm sage
vocal roost
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so for example:

Taking the derivative of 2xy with respect to y.

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that's 2x

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right

vivid halo
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yeah

storm sage
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that is a partial derivative

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yes

vocal roost
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ah

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i get it

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hold on, isn't that 2y then?

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no wait

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im mixing it up, nvm

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2x would be treated as a constant, so it makes sense for it to be 2x if it's with respect to y.

storm sage
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yes if it's a partial derivative

vocal roost
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ye

finite tusk
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Let F(x,y(x))=0
Then dF/dx(dx/dx)+dF/dy(dy/dx)(dx/dx)=0
Then dF/dy(dy/dx)(dx/dx)=-dF/dx(dx/dx/

dF/dy(dy/dx)=-dF/dx
dy/dx=-(dF/dx)/(dF/dy)
dy/dx=-(dFdy)/(dxdF)
differentials anti commute so
dy/dx=-(-dydF)/(dxdF)
dy/dx=(dy/dx)(dF/dF)
therefore dy/dx=dy/dx
Since differentials anti commute dxdF is also -dFdx

mint canopy
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This is gibberish

vocal roost
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säääääääääääääääääääääääääääääääääääääääääääääääääääääääs

mint canopy
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F(x,(y(x))

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what

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are there missing brackets, or is there an extra comma, what is this

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differentials anti-commute
Why are you doing this if this is a multivalued fn, this makes no sense for partials

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therefore dy/dx=dy/dx
????????? I could've told you that beforehand

finite tusk
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It's an actual proof from a multivariable calc book

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F is a function of x and y(x)

mint canopy
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I think you MIGHT have missed some details out

finite tusk
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I did not

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Lol

neat lintel
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post a screenshot

finite tusk
#

If I did then elaborate

mint canopy
#

I literally just put up three things that don't make sense

finite tusk
#

Where

mint canopy
#

F(x,(y(x))
Count the brackets.

finite tusk
#

The equation is set how it is lol

neat lintel
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geo post a screenshot of the book

finite tusk
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Sorry F(x,y(x))

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This is what I meant

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Thank you

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Typo

mint canopy
finite tusk
finite tusk
mint canopy
#

Oh my fucking god

mint canopy
neat lintel
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holy fuck you're obnoxious lol, all i asked for was a screenshot

finite tusk
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Let's say F=x^2+xy^420+ y^69 which is in R^3

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But you would want to find dy/dx whcih is spanned on R^2

mint canopy
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I'm so glad I don't live in a drywall house

finite tusk
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Then use dy/dx=-F_x/F_y

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There happy?

finite tusk
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I'm pretty sure you can find it

mint canopy
storm sage
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what is going on lol

neat lintel
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no you fucking knob, i just want to know what book it was

finite tusk
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Calc 3

mint canopy
storm sage
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😭

storm sage
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I believe

mint canopy
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Like your "theorem" concluded that dy/dx = dy/dx,

storm sage
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when F defines a level curve

mint canopy
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so wtf is your theorem proving

finite tusk
storm sage
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What

neat lintel
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i can't wait for you to get banned

mint canopy
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Also, are you using d as a partial or an ordinary dervative?? You are not giving us all the info

finite tusk
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The thing I showed was 1st differentials anti commute

storm sage
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I can't tell if you are trolling

finite tusk
mint canopy
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Hhaaaaaaaaaaaaaaaaaaaa

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Oh my god

finite tusk
mint canopy
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Oh my god

storm sage
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.-.

dapper badge
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geo, people have explained to you what an empty space is and what a ring is

vocal roost
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AAAAAAAAAAAAA

dapper badge
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the least you could do is provide some context for your "result"

sleek wing
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Ban central

mint canopy
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Yeah, you made the right choice switching to physics for sure

finite tusk
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1st I showed differentials anti commute
2nd you can find the line tangent to F spanned on R^3 starting from some F which is in R^3

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Like a level curve

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When z=0 plane

mint canopy
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I don't think differentials anti-commute for partials, I think this is just not meaningful

finite tusk
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Seriously I'm amazed you don't know this

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I'm actually laughing so jard

storm sage
mint canopy
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Jesus christ

vocal roost
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my brain is bleaching

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so hard

sleek wing
finite tusk
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If you take Calc 3 you'll see this

finite tusk
sleek wing
#

I’ll see utter bullshit? Yeah probs

storm sage
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what do you mean by multiplying differentials? are you taking the exterior product?

finite tusk
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It was only fair

neat lintel
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geo stellar, may i ask what book you got this proof from?

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🙂

vivid halo
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tfw rediscovering the exterior algebra but worse

sleek wing
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PauseChamp

finite tusk
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Yes

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This book

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Go to the chapter that talks about trees

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And the problem is right there

storm sage
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okay I will look

finite tusk
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It's literally the exact same thing

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Ok

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It's nearing the end

mint canopy
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I can't wait to see this

finite tusk
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If it's not in the examples then it's one of the actual problems that ask you to prove that dy/dx = -F_x/F_y

wild lantern
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What chapter?

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I own that book lol

finite tusk
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I owned two of them

storm sage
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Lol

finite tusk
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What school do you go to?

mint canopy
finite tusk
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Lol

wild lantern
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Oh fuck me too actually lmao

finite tusk
wild lantern
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An older ed and the one you posted lol

sleek wing
#

Why did you own two copies of the same book

mint canopy
finite tusk
storm sage
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👀 are you spanish-speaking

sleek wing
finite tusk
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And it looked like trash carrying it around

wild lantern
finite tusk
#

So I got another

storm sage
finite tusk
finite tusk
wild lantern
storm sage
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tf

wild lantern
#

Welp not super heavy req

finite tusk
#

Expensive book

mint canopy
#

America moment

storm sage
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why???

wild lantern
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Usually the profs don't care if you own it

finite tusk
#

I believe that book was about 220 dollars

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Or 200

wild lantern
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It's just the one they all followed at the time

finite tusk
#

In hardcore is all I knew that they sold it in

wild lantern
#

They switched to stewart now i think

finite tusk
#

Hardcover

vivid halo
#

undergrad courses: you must buy this textbook soyrage
grad courses: here's a site where you can pirate the three books for the course chad

finite tusk
wild lantern
#

It's pretty popular textbook geo

vivid halo
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"if you feel uncomfortable pirating the book just email me and I will send you my pirated copy"

vocal roost
#

mods: ^^
do not talk about pirating things

vivid halo
vivid halo
velvet dagger
wild lantern
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I pirate at my computer

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It's not a secret

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Jk lol

velvet dagger
#

Measure theory prof: "The content of this class is covered by finitely many books"

finite tusk
#

Banned

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Lol jk

mint canopy
#

you know, what if there was some kinda library at the beginning of time. Like a library of genesis

velvet dagger
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Not lol jk

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I'm about to ban dootdooter

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Any last words?

wild lantern
#

Pls no bulli

velvet dagger
#

,ban_irl DootDooter

fathom swallowBOT
#

Couldn't find a member matching _irl DootDooter!

mint canopy
#

HAHAHA

finite tusk
#

Lol

storm sage
#

imagine if there was a person whose name was _irl DootDooter

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and they just got banned

velvet dagger
#

It'd ask me to confirm lol

storm sage
#

Lol

finite tusk
#

When the power gets to the head

wild lantern
#

_irlDootDooter is a pretty good choice of username ngl

storm sage
finite tusk
#

You get P=W/changet

finite tusk
storm sage
#

pain

finite tusk
#

But it's with the differentials in 3d

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Like I said nearing the end

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Before curls and flux

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And divegrence

storm sage
#

okay I will look

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I am curious what you were trying to say now

finite tusk
#

After normal tnagent accelerations

wild lantern
#

Ch 12 in my older copy?

finite tusk
#

I'm not here to lie I am a seeker of truth

mint canopy
#

Seek that truth

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You keep seeking

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Wait no

finite tusk
#

I genuinely like this type of thing and I don't like to lie or mislead

mint canopy
wild lantern
#

This?

mint canopy
#

Maybe work on that

finite tusk
#

Yes

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Thank you

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Justice has been made

wild lantern
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Yeah this is from sec 12.5 in my copy

mint canopy
#

LMAO I WAS RIGHT, YOU WERE MISSING OUT THE PARTIALS

finite tusk
#

Except the partial can be a d

mint canopy
#

HAHAHA

finite tusk
#

They have d for dx/dx

wild lantern
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But idk how this shows differentials anticommute?

mint canopy
#

And there's nothing where you commute the differentials, bc you can't do that with partials mixing with ordinary diffs

finite tusk
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Because using the right hand side you can get the left hand side

mint canopy
#

Yeah like Geo, you wrote nonsense

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The notation wasn't even there

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Thanks for being like, "I can't believe you don't know this"

finite tusk
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Sometimes they used partial

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Sometimes they used the standard d

mint canopy
#

Yeah, and you never used them correctly

finite tusk
#

Bruh you can literally switch some D's and partials and the idea is literally the same

mint canopy
#

They are extremely different

finite tusk
#

dx/dx is the same a partialx/partialx

mint canopy
#

It makes, dare I say, all the difference

finite tusk
#

They are different but on on some cases

eager reef
mint canopy
#

Especially in this case, the distinction is important

finite tusk
#

Not everytime lol

neat lintel
#

geo stellar doing their best mochizuki roleplay (it doesn't matter how good you are at something if you explain it poorly and rudely)

mint canopy
#

This time.

storm sage
#

do you mean this

finite tusk
#

partial f/partial y is distinct from dF/dy

storm sage
#

this theorem is correct

finite tusk
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Yes

storm sage
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I couldn't find what you were talking about earlier though

finite tusk
#

I forgot to simply put some of the D's to partial

finite tusk
#

Before it should be a proof

wild lantern
#

Interuniversal Geo_Stellar theory realshit

storm sage
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do you mean this

finite tusk
#

yes sir

storm sage
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okay but what were you saying when you said "differentials anticommute"

finite tusk
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dy/dx= -F_x/F_y is what I said but I forgot to put partial for the dF/dy partial

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And for dF/dX

mint canopy
#

you literally just ended your proof with "therefore dy/dx = dy/dx" diligentBleak

eager reef
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Differentials do what

wild lantern
#

Therefore 1=1 woke

mint canopy
#

Also, you mixed partials and ordinary differentials, so you can't even mix it

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anticommute* it

finite tusk
storm sage
#

oh

finite tusk
#

In physics in grassmanian Geometry we see differentials anticommute

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So which is why I don't see it necessary to justify that to someone that doesn't believe me

dapper badge
#

ok but you didn't show it

finite tusk
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Yeah

storm sage
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okay I don't think that's the right way of putting that

mint canopy
#

This is the exterior derivative tho, it's not true that dxdy = -dydx, this is still wrong

storm sage
#

because you can't literally multiply out dy and dx in this equation

finite tusk
#

Its the idea that is used

mint canopy
#

Eric brings up another point

finite tusk
mint canopy
#

I'm going to implement some self-care

storm sage
#

I don't really understand, but I think you are struggling to articulate what you want to say formally

finite tusk
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Idk how else to put it then it write it out in in paper

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I'm not struggling to articulate what I'm saying

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Simply differentials anticommute

dapper badge
#

are you claiming that you proved this or not

finite tusk
#

It's already proved

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I didn't prove it

finite tusk
#

Prof Nima Arkani Hamed proves it in his lecture on Grassmanian

dapper badge
#

Ok it's just confusing because earlier you said "I showed differentials anti commute" when you didn't

finite tusk
eager reef
#

Are you referring to the fact that differential forms are skew symmetric

storm sage
#

you start with $$\f{\dd y}{\dd x} = -\frac{\f{\partial F}{\partial x}}{\f{\partial F}{\partial y}}$$ which is correct, and then you cancel out the fractions which is nonsensical

fathom swallowBOT
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Eric Tao (he/him)

finite tusk
#

Yes thank you

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Ime that

storm sage
finite tusk
#

Like that

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It's cuz you're not adding / so you're not making any justice

storm sage
#

what on earth do you mean by (dF dy)/(dF dx)

finite tusk
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I was very clear with what I wrote

storm sage
#

okay you are either trolling or are unwilling to answer the question, I will just ignore you

finite tusk
#

I'm looking back for it

dapper badge
#

timo is that a new pfp

eager reef
#

Different account

dapper badge
#

ah

mint canopy
eager reef
#

What algebraic structure are you feeling like today @dapper badge

finite tusk
#

I put -(dFdy)/(dxdF)

dapper badge
#

mmm

mint canopy
storm sage
#

yes

dapper badge
#

woke up feeling like a local ring

storm sage
#

what on earth do you mean by that

mint canopy
#

But one big one??? sick

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I respect that

dapper badge
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i'm noncommutative

eager reef
#

Might compute the maximal ideal later?

mint canopy
eager reef
#

Ooh the left or right one then

storm sage
#

noncommutativity is a plus

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you are more general

dapper badge
#

I actually forgor how the conditions work for noncommutative

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is it that left and right jacobson coincide?

finite tusk
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Just to expand upon it plz

mint canopy
#

Not a clue, damn

finite tusk
#

So I can explain

mint canopy
#

Making me feel bad about my knowledge of local rings

dapper badge
#

it's ok

eager reef
mint canopy
#

Hey did you know that you can detect singular points on a variety by looking at the global dimension of the local ring? Pretty cool huh

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No idea how that works

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But I know it does

eager reef
#

Funny words magic man

dapper badge
#

need to work on algebra stuff today, I been slacking

mint canopy
#

The global dimension is infinite exactly when the point is singular

vivid halo
#

have you thought about what this looks like for some simple examples?

eager reef
#

Need to work on diffgeo stuff

storm sage
#

okay $$-\frac{\partial F \partial y}{\partial x \partial F}$$

fathom swallowBOT
#

Eric Tao (he/him)

storm sage
#

what on earth do you mean by this @finite tusk

mint canopy
#

I realised recently that the Galois theory course that I took in my final year was really bad, so I want to read a good Galois book

dapper badge
#

i'm just getting to the good stuff but feeling a bit burnt out

mint canopy
#

I should look into this in the future

eager reef
#

Instead I am here reading that someone is saying differentials are anticommutative

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What’s wrong

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With my English

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man

vivid halo
#

differentials do anti-commute in a certain sense but idk if we are talking about that sense here

mint canopy
finite tusk
#

At 2:29:09 he describes that differentials anticommute

#

Watch at least like a minute it's right there

vivid halo
#

do you know in what sense he means this

finite tusk
#

As an anti synnetrized product

mint canopy
#

He doesn't mean in multiplication, I have said this a couple times now ughdhudsahjfd

#

Idk why I'm replying

finite tusk
#

But he only said as an anti synnetrized product to make the equation work

mint canopy
#

I said it was nonsense from the start

eager reef
mint canopy
#

Here's something cool

eager reef
#

Take care of yourself catKing

mint canopy
#

I notice that the number of help channels that are open increases/decreases at different times of day

vivid halo
mint canopy
#

I just thought that was cute. I guess it's clear that most people asking questions are from the US and Canada

eager reef
#

Geo stellar what you’re saying is correct in a sense

#

But in a sense that you don’t seem to know about

finite tusk
#

lolLLL

#

I just heard it too

mint canopy
#

Cargo cult math lol

vivid halo
#

also to be clear the explanation you gave isn't really a proof

eager reef
#

That’s the thing

vivid halo
#

like it's morally true but there's a lot more work you need to do to make this precise

dapper badge
#

thanks friend. sometimes I set personal goals for myself so I feel a bit disappointed when I don't meet them. I wanted to finish Aluffi this summer (ideally by the end of July) but that's probably not happening. You're right though, think I ought to take a small break so I'm not already burnt by the time fall semester starts lol

vivid halo
#

and you seem to be handwaving those steps

#

by like

finite tusk
vivid halo
#

idk citing Nima

finite tusk
#

Can you show me on a proof then

storm sage
#

this comes down to 1) how are you defining differentials 2) how are you defining multiplication of differentials

finite tusk
#

What exacrly it means for differentials to anticommute

mint canopy
eager reef
#

Do you know what those forms are

finite tusk
#

According to the video

vivid halo
#

you have to know what differential forms are

finite tusk
#

Go on

mint canopy
#

Idk why you guys are still going ngl

eager reef
#

Now you look at the definition

vivid halo
#

and then you have in the exterior algebra e.g. dx\wedge dy=-dy\wedge dx, this is the sense in which they anti-commute

eager reef
#

As sections of exterior powers

storm sage
eager reef
#

You need more background here

mint canopy
#

Like fr Eric, your goals are beyond me

finite tusk
#

So when this grassmanian Geometry is something I've been recently going in with another person

#

I'm not fully 100 percent knowledgeable at like most physicists

storm sage
finite tusk
#

But I guess I heard him say differential anticommute

#

And I applied it to some basic calc 3

storm sage
#

it was mentioned in our linear algebra textbook

vivid halo
#

the way you have to make these arguments that involve algebra with differentials precise is using the exterior algebra an making heavy use of like, isomorphism between a vector space and its double dual, and evaluating vectors on covectors and so on

dapper badge
# mint canopy How are you finding Aluffi? I am looking for graduate books in algebra

I absolutely love it, I had little experience with algebra before aluffi (I think I had only read Pinter's book) but I like his exposition a lot and the categorical perspective feels pretty unifying. My only gripe is the field theory chapter, but that might just be because this is my first time learning field theory. I found it a little too abstract for a first run so I want to go back and be more hands on with it

finite tusk
#

Thinking that differential form would work

mint canopy
finite tusk
#

Sorry if I made a hassle out of it honestly

storm sage
finite tusk
#

Its difficult in text

storm sage
eager reef
finite tusk
mint canopy
#

So hearing about Aluffi's approach is very valuable for me rn

vivid halo
#

the point is that when you write dxdy you're really talking about dx\wedge dy in the exterior algebra

eager reef
finite tusk
storm sage
storm sage
eager reef
#

How are you gonna have this talk without knowing what a wedge is

eager reef
#

You need way more background

storm sage
#

The is the first of a series of videos devoted to differential forms, building up to a generalized version of Stoke's Theorem. Here we look at the notion of a tangent space to a curve at a point and the tangent space of R^2.

Please Subscribe: https://www.youtube.com/michaelpennmath?sub_confirmation=1

Personal Website: http://www.michael-penn....

▶ Play video
eager reef
#

I thought bprp only solves funny looking integrals

storm sage
#

it's michael penn, not bprp

eager reef
#

Oh

#

LOL

#

Saw penn

#

Brain went to bprp

finite tusk
#

I understand the wedge product

dapper badge
finite tusk
#

a^b=-b^a

#

We can say one is a positive orientation and the other a negative orientation

mint canopy
#

Fair enough. I'll give Aluffi a chance then

finite tusk
storm sage
#

a wedge b is like a signed area element

dapper badge
mint canopy
#

Ya might be fun

storm sage
#

b wedge a is the same area with opposite sign

finite tusk
finite tusk
#

I would say it is

#

Like a cross product of a and b if a was a vector and also b

storm sage
#

yeah it's like a cross product

#

sort of

finite tusk
#

The abs value of cross product of dx x dy is dA in vector

#

Almost close yes

#

@storm sage @vivid halo if I have more questions on these type of these y'all think y'all can help?

plucky zodiac
#

@finite tusk sorry did not answer as have to take care of things but did reply

storm sage
vivid halo
finite tusk
#

Thanks guys, but just as far as you can help is always fine

plucky zodiac
#

Did it Eric

vivid halo
finite tusk
#

I understand

vivid halo
#

I am happy to answer quick questions though 🙂

finite tusk
#

Of course thank you very much 😊

storm sage
#

wait is it not diff geo lol

#

aren't you doing geometry with diff forms or something

neat lintel
finite tusk
#

Yes

plucky zodiac
#

Did it

rotund cove
#

just ripped a fat one on the last day of class. not even flustered

#

do any of u smarts ones hold it in? i swear i've never seen a smart guy fart

ancient flame
#

can we pin this

cold needle
#

bruhnion

ancient flame
#

hi metal

cold needle
#

hello

ancient flame
#

how's life

wooden flax
#

Hi Moddy!!

ancient flame
#

hi invictus!

wooden flax
#

how r u

ancient flame
#

im good

#

hbu

wooden flax
#

p good

ancient flame
#

that's good

wooden flax
#

yeah i guess

fierce abyss
#

How do you read those kind of letters in English? Flourish A/B/…?

full isle
#

$\mathfrak A$

fierce abyss
fathom swallowBOT
#

Mary Majok

fierce abyss
#

I mean read

full isle
#

script {letter}

fierce abyss
#

Like giving a speech or lecture something

full isle
#

Yes

#

just call it script

fierce abyss
#

Thanks

full isle
#

you usually only need to prefix with script,italic,bold,big,small {letter}

#

when speaking

#

script is just anything that looks like different font

#

every other prefix self explanatory

fierce abyss
#

Thanks. I have one more question. How do you read $^{b}A,{b}A,A^{b},A{b}$ respectively. Where $A^{b}$ doesn’t necessarily represent power, could be something like cohomological groups

fathom swallowBOT
#

Cogwheels of the mind

full isle
#

you will never see first one or second one really atleast for me

fierce abyss
#

I have seen them several times

#

Just don’t know how to read it

full isle
#

what context

#

for the last two you can say a upper b or a sub b

#

or a lower b

fierce abyss
full isle
#

also it depends on context

fierce abyss
#

Above proposition 11

full isle
#

they are using it for indexing?

#

personally that just looks like notation that you shouldnt be verbalizing

#

but if you need to you can just say what the object is

fierce abyss
#

Okay so if I want to read $^{I}E_{2}^{p,q}$, does “E sub 2 sup p comma q of the first type” sound natural to you?

full isle
#

you most definitely shouldnt worry about verbalizing this though

fathom swallowBOT
#

Cogwheels of the mind

full isle
#

its bloated notation with double indexing too. its never going to sound natural

#

you can just say what is understood to whoever you speak to

#

if its actually relevant to address the object

#

the whole point of notation isnt so that you can compactify the verbalizing

#

its just compactifying the idea of the object

#

no need to worry about verbalizing everything

fierce abyss
#

Okay, thanks. As long as i can make others understand what I am saying right

full isle
#

yeah and it shouldn’t be a problem if they have all senses

fierce abyss
#

Okay got it

rich rapids
#

wow, Gauss was mean af

charred mortar
#

Yeah Gauss had some savage moments

#

Once Jacobi came over to Gauss to discuss some cool new stuff Jacobi had found

#

Gauss opens some old drawer and is like “oh cool, I discovered that years ago but didn’t think it interesting enough to publish”

#

Jacobi counters by responding: Funny, you’ve published worse results

#

Gauss was honestly an ass

rich rapids
#

terrible human being

charred mortar
#

It’s a classic case of never meet (or in this case read about) your heroes

rich rapids
#

poor Bolyai was 21

charred mortar
#

Yeah Gauss really didn’t need to do that to poor Bolyai

rich rapids
#

wholesome:

'If this depresses you, turn your thoughts to the uplifting counterweight of Leonhard Euler. An intellectual volcano erupting
with wildly original thoughts (some of which we shall meet later) he was also a kind and generous spirit. We cite one, parallel example. When the then-unknown 19-year-old Lagrange wrote to him with overlapping discoveries in the calculus of variations,
Euler wrote back: “. . . I deduced this myself. However, I decided to conceal this until you publish your results, since in
no way do I want to take away from you any of the glory that you deserve.” See Gindikin (2007, p. 216). Incidentally, Euler
also personally intervened to rescue Lambert’s career!'

charred mortar
#

Oh yeah Euler was a great guy

#

He could certainly afford to give some credit to other mathematicians

#

Gauss could too tbh, he just chose to be a dickhead instead

rich rapids
# rich rapids

Visual Differential Geometry and Forms: A Mathematical Drama in Five Acts (2021) by Tristan Needham

in case anyone is interested

mint canopy
surreal rose
#

What is this equation

rich rapids
#

stokes

compact tartan
#

generalized stokes law

surreal rose
#

what does the subscript mean on integrals

compact tartan
#

what you're integrating on

surreal rose
#

like dx?

compact tartan
#

no

odd narwhal
#

The region you are integrating over

compact tartan
#

there's some region Omega and the theorem relates an integral over Omega to an integral over the boundary of Omega

surreal rose
#

Is this first year uni stuff?

#

And is it more physics or maths

compact tartan
#

no that's closer to 2nd or 3rd year

surreal rose
#

Alright fair enough

compact tartan
#

it's math but it's closely related to physics

surreal rose
#

If i do a maths degree will i be able to learn it?

compact tartan
#

special cases of this formula come up in electromagnetism

#

in fact stokes was working on both kinda

surreal rose
#

As in physics and maths?

#

I want to learn electromagnetism too, maxwells equations are taught first year uni right?

compact tartan
#

depends but also probably not?

#

I had EM in third semester

surreal rose
#

I’m in my last year of high school right now, we briefly looked at maxwells equations in physics but didn’t go into any of the maths, they look interesting

surreal rose
compact tartan
#

applied math and physics

surreal rose
#

Cool, i wanna do maths too

compact tartan
#

we didn't actually discuss the fully general stokes theorem in any class

#

but I was aware of it due to my own reading

surreal rose
#

Oh alright

compact tartan
#

intuitively it is a simple result but the proof is complicated by technicalities of analysis on manifolds

surreal rose
#

Is analysis on manifolds the same thing that made the poincaré conjecture proof so hard

compact tartan
#

uh

#

I'm not too familiar with that result

#

seems unrelated other than the fact that they're both involving manifolds

surreal rose
#

Oh alright

odd narwhal
#

Poincare conjecture is a result on topological manifolds

#

iirc

surreal rose
#

Ahh yeah

compact tartan
#

yeah I would be very wary of generalized stokes with relaxed smoothness conditions

green sapphire
#

I was doing a physics question and it was to calculate the displacement of an object when it covers 3/4th of the circumference of the circle of radius r
answer is D=sqrt2*r
=> That D/r=sqrt2

#

but sqrt2 cannot be represented in p/q

pure sun
#

Sqrt(2) = sqrt(2) / 1

bright hill
#

lmao

neat lintel
#

its not funny

bright hill
#

if you say so

woven whale
woven whale
green sapphire
#

2x=0
2x/x=0/x
2=0

#

how

surreal sapphire
#

the first equation implies x = 0, so you are dividing by 0

green sapphire
#

transposing

#

we can transpose x also

surreal sapphire
#

what does that mean

green sapphire
#

like
2x=4
x=4/2
x=2

#

but

#

2x=4
2=4/x

#

also

bright hill
surreal sapphire
#

you can only divide both sides by a number if this number is nonzero

green sapphire
#

what?

surreal sapphire
#

what you call "transposing" is dividing both sides of an equation by a number

#

this is only possible if that number is not 0

green sapphire
#

oh

#

ok

surreal sapphire
neat frost
#

Wat

#

Why math not in math mode

surreal sapphire
#

slurp you found the one issue

neat frost
#

Yessir

#

I bet it would all make sense if typeset correctly

surreal sapphire
#

proof by nicely typeset

green sapphire
#

umm.

#

What do you want elaboration of?

neat frost
#

Everything

#

None of it makes sense

green sapphire
#

hmm

surreal sapphire
#

ye, this is mostly word salad

#

and i dont feel like trying to decypher it by asking more questions, since the conclusion is also just wrong

#

and i doubt this is a good faith misunderstanding

mint canopy
#

Could be written by an ai lol

sacred forge
#

pretty funny

bright hill
#

this must be a copypasta opencry

wispy pike
#

Does anyone have a recommendation for some sort of ipad/drwawing pad for roughly 200 euros? I have ver ybad vision so one short problem fills almost half a page haha

neat lintel
eager reef
#

@sleek wing found your alt

queen sierra
#

Fit a 7x7 matrix in 2 lines :))

arctic grove
#

that is most definitely easy still

#

considering they fit a 5 by 5 in 1 line

#

lol

neat lintel
#

I found the flow of the PDE hyperthonk

#

i can fit a 20x20 matrix in 1 line

#

It took hours of online reading/repeated solving

#

Yeah

shrewd cliff
#

Hey, does anyone ever get humiliated for loving maths here?

chilly coral
#

You love maths? 🤮

shrewd cliff
#

Um, yeah, I do. I thought this was a maths group?

woven whale
#

no wtf???

#

this is a math hater group

#

we all hate math

#

🤢

chilly coral
#

It's a very toxic relationship

shrewd cliff
#

are you joking?

neat lintel
#

dont listen to them, people only get humiliated for not loving math, not for loving it

shrewd cliff
#

I don't know how to do that. You see, even my parents don't seem to get it for some reason🙁 it's like they just don't care about the things I like and don't like

neat lintel
#

well if they don't care about you, you shouldn't care about them either

#

just do your thing, and fuck everyone else in the world

shrewd cliff
#

Well, it's hard, I just can't stop myself from taking every small thing they say to heart

neat lintel
#

yeah, its just like an hard theorem. at first it seems really hard and you feel like you cant prove it. but keep trying it

#

in the future you'll look back at it and find it trivial

fervent flame
#

change ur pfp

shrewd cliff
neat lintel
#

well noone humilliated me for loving math

#

and its really weird if someone does that lol

#

if they do that they're weirdos and you shouldn't care about them

chilly coral
#

I get called a nerd sometimes but it's never in a bad/humiliating way

chilly coral
shrewd cliff
shrewd cliff
neat lintel
#

i m curious btw, what kind of math you like?

shrewd cliff
#

what do you mean by what kind?

rich hamlet
#

7x7 in one line

#

on a computer tho

#

so ig i cheated bc i can zoom in

neat lintel
#

what areas

zenith forge
fervent flame
#

stfu silver

shrewd cliff
# neat lintel what areas

Hmm, I love basically everything, like any math topic seems interesting to me. But I especially love trigonometry ,algebra and patterns. What about you?

rich hamlet
#

what area in algebra do you mean?

neat lintel
#

i like category theory, set theory, algebra, idk much about them yet tho

rich hamlet
neat lintel
#

polish space stuffs seems interesting

rich hamlet
#

where its like "you like math?? the fuckkk?"

#

its either "wow thats cool" or "i suck at math"

#

but in reality they think we are a different species lets be honest now /j

neat lintel
#

idk why people only say that for math usually

#

i suck at everything

rich hamlet
#

its bc its accepted to suck at math

#

like its a desirable quality

#

math is not something most people want to "improve" in

neat lintel
#

why would it be a desirable quality

#

its fine if you dont want to improve in it

rich hamlet
rich hamlet
#

u dont have to love math

#

theres nothing wrong with not loving math

#

its really not that big a deal tho

neat lintel
#

i dont really want to learn politics or biology, but i dont think its "good" that im bad at those

rich hamlet
#

but i dont go out of my way to learn it

rich hamlet
#

he starts with categorical principles

neat lintel
#

yeah i already did

rich hamlet
#

ah yeah

#

im not knowledgeable at all in algebra compared to analysis

#

i am just touching the tip of analysis too, but ive definitely done more in analysis

neat lintel
#

im not much knowledgeable in anything tbh

rich hamlet
#

yeah i think as i learn more theres just even more that i dont know

queen sierra
rich hamlet
#

which is the expected outcome

queen sierra
shrewd cliff
#

@neat lintel are you in high school?

neat lintel
#

no

#

im just an undergrad

rich hamlet
#

@shrewd cliff are u in hs?

shrewd cliff
#

@rich hamlet yeah, 10th grade

rich hamlet
#

from the us?

shrewd cliff
#

no

rich hamlet
#

i see

#

@neat lintel i mainly got lost at universal properties

#

i dont get the langauge that they use

#

like "object A in C is universal in that there exists a unique morphism from A to Z for any object Z in C" vs. just saying "A is initial in C"

#

i mean ig its pretty cool that initial and final objects are isomorphic but its not exactly clear to me why we care

fervent flame
neat lintel
#

initial and final objects are not isomorphic in general

fervent flame
#

so cringe

rich hamlet
neat lintel
#

yeah

rich hamlet
#

thats what i meant

#

sorry bad wording

neat lintel
#

uniquely isomorphic even

rich hamlet
#

thats the whole "universal property" part

#

from what i understand its basically about uniqueness

#

its about unique relationships between certain objects from what i understood

#

the product/coproduct example made it clearer

neat lintel
#

universal properties are kinda the most efficient way to construct something

#

for example the product of 2 sets AxB

rich hamlet
#

yeah

neat lintel
#

actually let me talk about the disjoint union

rich hamlet
#

my goal is to be able to write abstract nonsense proofs basically

neat lintel
#

AuB

rich hamlet
#

mhm

neat lintel
#

its all that you need to have to have inclusion of A and B into it

#

you could have more elements

#

but its not needed

#

AuB is the most efficient way to do it

rich hamlet
#

this is shown in 1.5 of aluffi right

#

i remember this

neat lintel
#

probably

rich hamlet
#

ur an undergrad right?

#

what year

#

also who is the girl in ur pfp @neat lintel

neat lintel
#

i am last year undergrad

drifting wharf
#

Can someone help me with a physics problem

ancient junco
#

Who is stronger, Goku or Sans?

bright hill
deep mango
#

Goku was a big part of big brother season 23. Final 4 eviction was messy!

bright hill
#

I've googled big brother a couple of days ago

#

shit got the lowest imdb score I've ever seen

#

I noped out so fast after seeing that lol

deep mango
#

What

#

Idk what that even means

#

How do you give an overall IMDb score to a game show with like 24 seasons

#

Some of the seasons are shit and some are godly

hollow sundial
#

episodes with vegeta: 9.0+
episodes with master roshi: 5.0-

deep mango
#

Lol

#

The episode with goku is very polarizing

#

Watching a car crash vibes

bright hill
#

how do you know which seasons to watch?

queen sierra
hollow sundial
#

seasons where goku makes a spirit bomb: 8.0+
seasons where goku makes a kamehameha: 9.0+
seasons where goku is scared of needles: 5.0-

fervent flame
#

ratio

queen sierra
#

Watched all of them basically even the films

hollow sundial
#

oh yea there are like 15 movies

queen sierra
#

Yuppp

hollow sundial
#

i think i stopped after Cell

#

but then watched Buu again. I never understood that saga

queen sierra
queen sierra
hollow sundial
#

Gohan is badass

queen sierra
#

I liked his mystic Form without the yellow hair and the fight with buu was one of my favourites

eager reef
#

But can he beat goku

deep mango
#

Honestly big brother the tv show is garbage and not worth watching mostly

#

The old seasons are quite good

#

Seasons 2-8, 10, 12, and 14 are all excellent. Then the show kind of gets up its own ass

queen sierra
#

I feel like Chichi brainwashed him 😭

deep mango
#

I just follow the big brother live feeds and podcasts cause I enjoy the gameplay and social strategy

#

I dont care about competitions or silly stuff

#

Survivor is a much much better show

ancient flame
#

hi ryc

deep mango
#

Hi gmod

ancient flame
#

how are u

eager reef
hollow sundial
#

okay but everyone else likes you. parent approval is overrated

eager reef
#

They need an educated one

#

Goku be stupid as hell sometimes

queen sierra
ancient flame
#

🍿

eager reef
#

Don’t summon it

ancient flame
#

LOL

#

"it"

delicate knoll
ancient flame
storm sage