Q5 of 127 Page 108

Evaluate the determinants

Now,

We know that a determinant of a 3x3 matrix is calculated as

= 3[0 – (-1)(-5)] +1[0 – (-1)(3)] – 2[0 – 0]

= 3(-5) + 1(3) – 0

= -15 + 3

= -12

The determinant of the above matrix is -12

If then show that |2A| = 4|A|.

If then show that |3A| = 27|A|