MCQ
If for the matrix $A, A^3=1$, than $A^{-1}=$
  • $A^2$
  • B
    $A^3$
  • C
    $A$
  • D
    None of these.

Answer

Correct option: A.
$A^2$
$A^3=1$
$\Rightarrow A^{-1} A^3=A^{-1} \mid$
$\Rightarrow\left|A^2=A^{-1}\right|$
$\Rightarrow A^2=A^{-1}$

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