A continuous-time sinusoid xa(t) with fundamental period Tp = 1/F0 is sampled at a rate Fs = 1/T to produce a discrete-time sinusoid x(n) = xa(nT).
(a) Show that x(n) is periodic if T/Tp = k/N (i.e., T/Tp is a rational number).
(b) If x(n) is periodic, what is its fundamental period Tp in seconds?
(c) Explain the statement: x(n) is periodic if its fundamental period Tp. in seconds is equal to an integer number of periods of xa(t).