The subsequent topic that we require to take a look at is the determinant of a matrix. The determinant is in fact a function that gets a square matrix and converts this in a number. The real formula for the function is somewhat complicated and definitely beyond the scope of this review.

The particular method for computing determinants of any square matrix is termed as the method of cofactors. Because we are going to be dealing almost exclusively along with 2 x 2 matrices and the occasional 3 x 3 matrix we won't get in the method now. We can provide simple formulas for all of these cases. The ordinary notation for the determinant of the matrix A is,

det(A) = |A|

Now there are the formulas for the determinant of 2 x 2 and 3 x 3 matrices is,