## power spectrum

Hi,

I want to sketch the power spectrum of the following Fourier transform function:

$\frac{cos(20.\pi.t)}{[1+t^2]}$.

the fourier transform of
$F(\frac{1}{[1+t^2]})=\pi*e^{-2.\pi.|f|}
$

I am a little bit confused about the frequencies and the magnitude of the power.
Can someone clarify me on this?
Thank you