DeterminantsThe symbol is a determinant of third order that consists of nine numbers arranged in three rows and three columns.
By definition, the value of a determinant of third order is given by:
|A| = a11a22a33+a13a21a32+a12a23a31-a13a22a31-a12a21a33-a11a23a33
and is called the expansion of the determinant.
To remember easily, you can use:
Express the value of the determinant: