Let A = Rmxn, b = Rm, D = R, and \ > 0. Consider the regularized least squares problem min||Ar 6|| + A||D.||. xRn Show that the problem has a unique solution iff null(A) null(D) = {0}, where the the null space of a linear map T, denoted by null(T), is the set of vectors x such that Tx = 0. A synonym for null space is kernel. Note that {0} is not the emptyset.|