An analog signal xa(t) = sin(480t) + 3sin(720t) is sampled 600 times per second. (a) Determine the

Question:

An analog signal xa(t) = sin(480πt) + 3sin(720πt) is sampled 600 times per second.
(a) Determine the Nyquist sampling rate for xa(t).
(b) Determine the folding frequency.
(c) What are the frequencies, in radians, in the resulting discrete time signal x(n)?
(d) If x(n) is passed through an ideal D/A converter. What is the reconstructed signal ya(t)?