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Homework Help: Evaluating a fourier series using the firs 100terms

  1. Aug 23, 2009 #1
    Well, the problem gave me a symmetric square wave f(x).

    f(x) = 1, when |x|<pi/2 and -1, pi/2 < |x|< pi

    I was able to solve for its fourier series expansion given by:

    f(x) = (4/pi) * [tex]\Sigma[/tex] (-1)n cos(2n+1)x / 2n+1

    Now the problem asked us to evaluate this series for x=0(pi/18)pi/2 using the first 100terms of the series.

    Now this is where i was really stuck, i can't seem to grasp the meaning of "from x=0(pi/18)pi/2". I'm not familiar with this notation. Can anyone enlighten me please?

    And if possible, point me in the right direction in evaluating this series?:) thanks so much!
  2. jcsd
  3. Aug 23, 2009 #2
    Welcome to PF!

    You have to take the first 100 terms, sum them up, call it some function S(x), and then find values of S(x) from x = 0 to x = pi/2, in steps of pi/18 (which is what the notation means).
    Last edited: Aug 23, 2009
  4. Aug 23, 2009 #3
    ooohhh!!! i seee!! thanks very much!! :D now i understand :D
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