Higher Concepts of Mathematics MATRICES AND DETERMINANTS Solution: A B (1x3)   (2x0)   (1x5)   (2x6) (3x3)   (4x0)   (3x5)   (4x6) 3 0 5 12 9 0 15 24 3 17 9 39 It should be noted that the multiplication of matrices is not usually commutative. The Determinant Square matrixes have a property called a determinant.  When a determinant of a matrix is written, it is symbolized by vertical bars rather than brackets around the numbers.  This differentiates the determinant from a matrix.  The determinant of a matrix is the reduction of the matrix to a single scalar  number.    The  determinant  of  a  matrix  is  found  by  "expanding"  the  matrix.    There  are several methods of "expanding" a matrix and calculating it’s determinant.  In this lesson, we will only look at a method called "expansion by minors." Before  a  large  matrix  determinant  can  be  calculated,  we  must  learn  how  to  calculate  the determinant of a 2 x 2 matrix.   By definition, the determinant of a 2 x 2 matrix is calculated as follows: A = Rev. 0 Page 21 MA-05