Provide a glimpse of some widely used matrix factorizations, some of which are discussed later in the text.
(Reduced LU Factorization) With A as in the Practice Problem, find a 5 X 3 matrix B and a 3 X 4 matrix C such that A = BC. Generalize this idea to the case where A is m X n, A = LU, and U has only three nonzero rows. 2