2. Let B E Rnxn be s.p.d. and C' E Rnxn such that A E Ranx2n defined as B CT A : C B+CB-1CT is s.p.d. B O (a) (2p) Find a block elimination matrix E satisfying EAET = 0 B Compute E-1. (b) (2p) Let LB ERnxn be the Cholesky factor of B. Compute the Cholesky factorization of A. (c) (2p) Let b E R2n. How is the Cholesky factorization of A used to solve Ax = b