Question

If A is a square matrix such that A² = A, then (I + A)² - 3A is ____________.

विकल्प

• I

• 2A

• 3I

• A

Answer 1

If A is a square matrix such that A² = A, then (I + A)² - 3A is I.

Explanation:

as (I + A)² - 3A

= I² + IA + AI + A² - 3A

= I + A + A + A - 3A = I