The frequency spectrum of a periodic signal x(t) is given below. Dn 0.25 1.35 1.0 0.5 0.35 20 40 60 On -45 -90- -135 -180 20 40 60 80 80 f (Hz) The shifted cosines form of x(t) is given by x(t) = Do + Dn cos (nwot + On) . n=1 1) Determine the fundamental angular frequency wo for x(t). 2) Find the shifted cosines form for x(t). 3) Compute the average power for x(t). f (Hz)