Question

Check whether the following matrices are invertible or not:

`[(3, 4, 3),(1, 1, 0),(1, 4, 5)]`

Answer 1

Let A = `[(3, 4, 3),(1, 1, 0),(1, 4, 5)]`

Then, |A| = `|(3, 4, 3),(1, 1, 0),(1, 4, 5)|`

= 3(5 – 0) – 4(5 – 0) + 3(4 – 1)

= 15 –  20 + 9

= 4 ≠ 0

∴ A is a non-singular matrix.

∴ A is invertible.