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Homework Help: Fourier Transform using Modulation

  1. Sep 17, 2011 #1
    1. The problem statement, all variables and given/known data

    Find the Fourier Transforms

    f1(t) = [itex]\frac{2}{3-it}[/itex]

    f2(t) = [itex]\frac{2}{3-it}[/itex]cos(t)

    2. Relevant equations

    F{H(t)et} = [itex]\frac{-1}{-1-it}[/itex]

    F{f(t)cos([itex]\omega[/itex]t)} = [itex]\frac{1}{2}[/itex][F([itex]\omega[/itex]+[itex]\omega[/itex]0+F([itex]\omega[/itex]-[itex]\omega[/itex]0)]

    3. The attempt at a solution

    For the first question, my answer was 4*pi*H(-[itex]\omega[/itex])e3[itex]\omega[/itex] from using the first eqaution F{H(t)et} = [itex]\frac{-1}{-1-it}[/itex] and using symmetry

    From there, I don't know how I would use the second equation to answer the second question.
    Last edited: Sep 17, 2011
  2. jcsd
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