Find the determinant

Question

|1 -1 3|

|0 -2 1|

|4  0 1|

Answer 1

Use the rule for expanding determinants to get 

 

1 * | -2 1 |  - (-1) * | 0 1 |  +  3 * | 0 -2 |

      |  0 1 |              | 4 1 |            | 4  0 |  

 

= 1 * (-2 - 0) + 1 * (0 - 4) + 3 * (0 - (-8))

 

= -2 - 4 + 24 = 18