Write the following MATLAB functions: •B = swap(A, i, j). Here A is an (n × n) matrix and, i and j are indices. The
function should take the matrix A and swap the rows i and j. Output the resulting
matrix as B.
• index = max entry(A, i). Here A is an (n × n) matrix and i is an index. The
function should extract the column i of A, and find the maximum (in modulus!)
entry of that column below the diagonal entry A(i, i) (including the diagonal
entry). Output the row index of the maximum entry in index.