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Homework Help: Fourier Series prob

  1. Oct 22, 2005 #1
    I've got parts of this problem but I'm stuck on some of the integration. See attached. Thanks!

    Attached Files:

  2. jcsd
  3. Oct 22, 2005 #2


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    First, since an interval is 0 to [itex]\pi[/itex] what are you integrating over 0 to [itex]\pi/2[/tex]?

    Second, since cos x is positive from 0 to [itex]\pi/2[/itex] and negative from [itex]\pi/2[/itex] to [itex]\pi[/itex], you can replace |cos(x)| with
    cos(x) from 0 to [itex]\pi/2[/itex] and with -cos(x) for [itex]\pi/2[/itex] to [itex]\pi[/itex].
  4. Oct 22, 2005 #3
    I changed the interval I was integrating over b/c that's part of the equation. You can't integrate from -l to l so you change it to 0 to l where l is half of the fundamental period and instead of multiplying the integral by 1/l, I changed it to 2/l. Is it easier to just integrate from -l to l?
    Last edited: Oct 22, 2005
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