Continuous-time signal x(t) is given as x(t)=0.5cos (100 xt)+cos (50xt) . (a) Assume a sampling frequency of wo,=250x Sketch X,(j), the spectrum of the sampled signal x,(t). Include at least three replicas. (b) Assuming an ideal reconstruction filter with cutoff frequency =/2, sketch the spectrum of the reconstructed signal X, (j) AND specify the reconstructed signal x, (t) in the time domain as an equation.