I probably should have defined some terms.
A matrix is a rectangular array (m by n) of numbers. It can be a single number (a 1 by 1 matrix) or any other dimension (m and n must be positive integers). A matrix is denoted by brackets on both sides.
A determinant is a value only given to a square matrix (where m = n). For a 1 by 1 matrix the determinant is the lone entry. For a 2 by 2 matrix
a b
c d
the determinant is (a)*(d)-(c)*(b).
The formula for a 3 by 3 matrix was mentioned above in my previous post.
Please don’t ask me to post the formulas for anything greater than m = n = 3, they are very long.
The determinant of a matrix is denoted by vertical bars on both sides. For example if we have a matrix named “A” then the determinant of “A” is denoted by |A|. There are also text books that put the vertical bars on both sides of the whole array to denote the determinant.