Obtain Fourier expansion

[warwick]

Unfortunately, I don't remember ever doing Fourier series expansions.

F is clearly an odd function. From looking at the answer in the book and referencing it with the brief Fourier series section in my mechanics book, a[sub:3j4fznum]n[/sub:3j4fznum] vanishes I'm assuming because cosine is even and it appears in the a[sub:3j4fznum]n[/sub:3j4fznum] formula. Why? I don't know. It also appears that A = 4. Where did that come from? Sorry, I'm lost. We might be covering this material tomorrow.

http://i111.photobucket.com/albums/n149 ... 1284950632

http://i111.photobucket.com/albums/n149 ... 1284950648

 

[warwick]

I worked it out last night and got

b[sub:11qdk8gl]n[/sub:11qdk8gl] = (wA/2pi)(1/n) cos(nwt') ]pi to -pi

That of course gives you zero for all n.