Question

If A is involuntory matrix ($A^2=I$) and I is 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 - $A^2$ = 0 ,

{Since A is involuntory, therefore $A^2$ = I }