(Correlated Brownian Motions) Let W(t) and U(t) be two independent standard Brownian motions. Let -1 ≤ ρ ≤ 1. Define the random process X(t) as X(t) = ρW(t) + √(1 - ρ^2)U(t), for all t ∈ [0,∞).
a. Show that X(t) is a standard Brownian motion.
b. Find the covariance and correlation coefficient of X(t) and W(t). That is, find Cov(X(t),W(t)) and ρ(X(t),W(t)).