Use either elementary row or column operations, or cofactor expansion, to find the determinant by hand. then use a software program or a graphing utility to verify your answer. 4 2 3 0 4 0 3 8 3 step 1: expand by cofactors along the second row. 4 0 3 2 4 8 3 0 3 = 4 step 2: find the determinant of the 2x2 matrix found in step 1. step 3: find the determinant of the original matrix.