Share

# If A is a square matrix such that A2 = I, then find the simplified value of (A – I)3 + (A + I)3 – 7A. - CBSE (Commerce) Class 12 - Mathematics

#### Question

If A is a square matrix such that A2 = I, then find the simplified value of (A – I)3 + (A + I)3 – 7A.

#### Solution

Given:

(AI)3+(A+I)37A

=A3I33A2I+3AI2+A3+I3+3A2I+3AI27A

2A3+6AI27A

=2A.A2+6AI27A

=8A7A

=A

Is there an error in this question or solution?

#### Video TutorialsVIEW ALL [2]

Solution If A is a square matrix such that A2 = I, then find the simplified value of (A – I)3 + (A + I)3 – 7A. Concept: Types of Matrices.
S