Question

If A and B are square matrices of order 3 such that ||=-1 and ||=4 ,

then what is the value of |3| ?​

Answer 1

Answer:

We know that

∣AB∣=∣A∣∣B∣

Also for a square matrix of order 3

∣KA∣=K

3

∣A∣because each element of the matrix A is multiplied by k and hence in this case we will have k

3

common.

∴∣3AB∣=3

3

∣A∣∣B∣=

=27(−1)(3)=−81