I think this is a joke, but I can't be sure.

Question

doc.brown · Answer

$$f(x)=a_0+\sum^{\infty}_{n=1}(a_n\cos\frac{n\pi x}{L}+b_n\sin\frac{n\pi x}{L})$$

slinley · Answer

wow, thats hard but lemme tryyyy

doc.brown · Answer

My director posted this saying it was the new wifi password.  I think he's being a smart retriceand I'd love to call him out on it.

slinley · Answer

Really?? lol well good luck for typing that in for wi-fi!!! lol im kidding.

one098 · Answer

When you figure out how to post that function as your wifi, tell me.

doc.brown · Answer

My director posted this saying it was the new wifi password.  I think he's being a smart... face... and I'd love to call him out on it.

slinley · Answer

u still typing?? Lol

doc.brown · Answer

Let say $x=1$ and $n=1$ then$$f(1)=a_0+a_1\cos\frac{1\pi 1}{L}+b_1\sin\frac{1\pi 1}{L}$$How can I clean up$$a_0+a_1\cos\frac{\pi}{L}+b_1\sin\frac{\pi}{L}$$?

slinley · Answer

umm hold on lemme solve it

anonymous · Answer

Thats the formula for Fouier series of a function. There is nothing to solve unless they give you f(x). Generally questions are of the form,, "Given a periodic function f(x)=(insert function here), solve for the fourier coefficients $a_0,a_n,b_n$."

anonymous · Answer

http://mathworld.wolfram.com/FourierSeries.html

anonymous · Answer

Example of a Fourier series problem: http://www.youtube.com/watch?v=nXEqrOt-nB8

doc.brown · Answer

Exactly what I thought, what course would teach the Fourier series?  I might as well learn it while I'm on the topic.

anonymous · Answer

Hmm....It can be taught in a Calc 2 or 3 course. I don't recall if thats generally where its taught though. It pops up in Applied Mathematics courses.

anonymous · Answer

Because all it really involves is integration.

doc.brown · Answer

Integral calculus.  Thanks!