4. (10 points) A damped wave train is expressed by f(t) = Ae-iwot when t2t> 0;…

4. (10 points) A damped wave train is expressed by f(t) = Ae-iwot when t2t> 0; and f(t) = 0 ortherwise. a) Please find the power spectrum of this light; b) Please plot and discuss the spectrum when to = 5