Define a random process $X(t)=A \cos \left(\omega_{0} t+\Theta\right),$ where $A$ and $\Theta$ are independent random variables; $\Theta \sim \operatorname{Unif(}(-\pi \pi, \pi] ;$ and $A$ has mean $\mu_{A}$ and variance $\sigma_{A}^{2} .$ (That is, $X(t)$ models a signal with both phase and amplitude variation.)
(a) Find the mean function of $X(t)$ .
(b) Find the autocorrelation function of $X(t) .$
(c) Is $X(t)$ wide-sense stationary?