Consider the signal x(t) = 10 cos(27-2000t)+3 sin(27-3000t). for t20 sampled at the rate of 8000 Hz, a.Sketch the spectrum of the sampled signal up to 20 khz b.Sketch the recovered analog signal spectrum if an ideal lowpass filter with a cutoff frequency of 4 khz is used to filter sampled signal in order to recover the original signal.