Question

Fourier series!
Find the series of cosines
f(x) = 1, 0 ≤ x < π/2
0, π/2 < x ≤ π

Answer 1

Here's one link you can refer to, with all the formulas you need. Fortunately, you only have to find the cosine series, so it's a matter of computing \(a_n\):
http://openstudy.com/study#/updates/51c9ad52e4b069eb00c69480

Here's another that works one out completely, but it's a wall of text and you'd have to sort out what you need:
http://openstudy.com/study#/updates/51b8663fe4b0862d04988ef9

Here's one that sets up the cosine series:
http://openstudy.com/study#/updates/51b78380e4b0862d049862ea

This one should be considered a footnote:
http://openstudy.com/study#/updates/51887634e4b06f6587cc6aa2

Regarding the last link, use those limits on the integral if the period of the given function is not \(2\pi\). In this case, \(L\) is the half-period.

Answer 2

You might have trouble seeing this, I hear there are problems with viewing code...

Answer 3

yes, is hard to see, the codes are not encrypted