Let X(t) = Acos(πt) + N be a random process, where A is a positive random variable with E[A] = 1 and Var[A] = 2, and N is a zero-mean unit-variance Gaussian random variable. Also, let us assume that A and N are independent.
(a) Plot a sample path as a function of time t.
(b) Find the autocorrelation function Rx(t1; t2).
(c) Find the autocovariance function Cx(t1; t2).
(d) Is X(t) ergodic?