MCQ
If $A$ is a square matrix such that $A^2 = I$, then $A^{-1}$ is equal to:
- A$A + I$
- ✓$A$
- C$0$
- D$2A$
✓
Answer
Correct option: B.
$A$
$A^2 = I$
$A^{-1}A^2 = A^{-1}I$
$A = A^{-1}$
$A^{-1}A^2 = A^{-1}I$
$A = A^{-1}$
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