Higher Concepts of Mathematics
MATRICES AND DETERMINANTS
(1x3) (2x0) (1x5) (2x6)
(3x3) (4x0) (3x5) (4x6)
It should be noted that the multiplication of matrices is not usually commutative.
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 its 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