30. Write a user-defined MATLAB function that calculates the determinant of a matrix by using the formula:

For the function name and arguments, use d3 = det3by3(A), where the input argument A is the matrix and the output argument d3 is the value of the determinant. Write the code of det3by3 such that it has a subfunction that calculates the determinant. Use det3by3 for calculating the determinants of:

(a) (b)