2. Consider a covariance stationary GARCH(1,1) process for an excess return series {rt}, where = rt+1 Ot+1++1 2 07+1 = w + ar + Bo (1) (2) where {z} is a sequence of independent standard normal random variables, w > 0 and a > 0, > 0, a + < 1. Show that the process {rt} is uncorrelated but not independent.