Observe the matrix; the matrix has 3 rows and 3 columns.
\So, the dimensions of matrix are
.
The determinant of a
matrix is called third-order determinant.
Evaluate the third-order determinant using expansion by minors method 
Find the determinant using third-order determinant definition.
Evaluate the
determinants using second-order determinant definition.




Product of two different sings is negative.
\
Product of two same sings is positive.
\


The determinant is
.