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Homework Help: Inverse Laplace Tranform

  1. May 30, 2006 #1
    <Inverse Laplace Transform>

    Hi, I was given this: F(z) = 1/(z^2)(z^2+1) and was asked to use its residues to compute f(t). [z is a complex number]

    The answer I got is -sin(t). But the answer on the book says t-sin(t).
    I double checked and the residue of z=0 is 0, I don't get where the t is from.
    Please, can anyone help? Thanks
     
  2. jcsd
  3. May 30, 2006 #2

    benorin

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    Homework Helper

    [tex]\frac{1}{z^2(z^2+1)}=\frac{1}{z^2}-\frac{1}{z^2+1}[/tex]

    hence f(t)=t-sin(t).
     
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