Question

Choose the correct alternative.

If A is a 2 x 2 matrix such that A(adj. A) = `[(5, 0),(0, 5)]`, then |A| = _______

Options

• 0

• 5

• 10

• 25

Answer 1

5

Explanation:

A(adj A) = |A| I

A(adj A) = `[(5, 0),(0, 5)] = 5[(1, 0),(0, 1)]`

∴  |A| = 5.