Question

For a matrix A, if $A^2=I$ where I is a unit matrix of same order, then (I - A)(I + A) is

• A. Zero matrix
• B. A
• C. I
• D. 2A

Answer 1

The correct option is A

Zero matrix

(I - A)(I + A) = I - $A^2$

= O ,

{Since $A^2$ = I (given) }