Fourier Expansion for a One-Period Function with Period 2pi

  • Thread starter Thread starter Kuma
  • Start date Start date
  • Tags Tags
    Approach
Kuma
Messages
129
Reaction score
0

Homework Statement



Given this one period graph of a function with period 2pi,

YpNoh.png


find a Fourier expansion.

Homework Equations


The Attempt at a Solution



So I was wondering if i can split up the integrals into two parts to find the coefficients. It is an even function so ak = 0.

for bk can I split the integral as follows

1/pi[int 0 to pi (x cos kx dx) + int pi to 2pi ((-x+2pi) cos kx dx]

?
 
Physics news on Phys.org
Yup, that's what you're supposed to do. Also, remember a0 isn't equal to 0.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top