suppose stochastic processes X(t),Y(t),and Z(t) are
independent and wide-sense stationary. If X(t),Y(t),and Z
(t)are periodic with period 2pi,3pi,3 respectively. Find
the period for the following autocorrelation functions
(i) RXY+ RYX
(ii)RXZ+RZX
(iii)RYZ+ RZY
(iv)RXY+ RYZ+RZX
if it is periodic
