Consider 4 A = 4 2 -1 7 1 3 (a) Use Gaussian elimination with scaled row pivoting to obtain the factoriza- tion PA = LU. Show all intermediate steps-multipliers, scale array s, and index array p, so the array that generates P, and the final array matrix a as it would appear after the algorithm had finished working on it. (b) How can you find | det(A)| based on what you have already computed?