(15 marks) Let {X(t), t ∈ R} be a continuous-time random process, defined as
X(t) = A cos (2t + Φ),
where A ∼ U(0, 1) and Φ ∼ U(0, 2π) are two independent random variables.
(a) Find the mean function µX(t).
(b) Find the correlation function RX(t1, t2).
(c) Is X(t) a widely stationary stochastic process?
