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Homework Help: Fourier Coefficients

  1. Mar 27, 2009 #1
    1. The problem statement, all variables and given/known data

    f(t) = 1 0<=t<T/2
    -1 T/2 <=t<=T

    ie. step function.

    frequency w_0 = 2pi/T

    2. Relevant equations

    3. The attempt at a solution

    What's the definition for the fourier coefficients a_n and b_n again? Not the one in wikipedia.
  2. jcsd
  3. Mar 27, 2009 #2
    Show us the work you have done on this. There are defining integrals for these coefficients, so set them up and try evaluating them.
  4. Mar 28, 2009 #3

    a_n = \frac{1}{\pi} \int_0^{T/2} 1*cos(nt) dt +\frac{1}{\pi} \int_{T/2}^{T} (-1)*cos(nt) dt


    b_n = \frac{1}{\pi} \int_0^{T/2} 1*sin(nt) dt +\frac{1}{\pi} \int_{T/2}^{T} (-1)*sin(nt) dt

    I think the normalization factor is incorrect, which is why i asked for the definition, I think it was 2/L where L is the length of the interval - i can't remember.
  5. Mar 28, 2009 #4
    If you can't remember, do you have a book?
  6. Mar 28, 2009 #5
    No, that's why I asked.
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