Question

If A and B are square matrices of order 3 such that |A| = –1 and |B| = 3, find the value of |3AB|

Answer 1

Given |A| = –1

|B| = 3

Given A and B are square matrices of order 3.

∴ |kAB| = k³ |AB|

Here k = 3

∴ |3AB| = 3³ |AB|

= 27 |AB|

= 27(–1)(3)

= – 81