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Determinants — Maths STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceMathsDeterminants1 Mark
MCQ
If $A$ is a square matrix such that $A ^2=1,$ then $A ^{-1}$ is equal to:
  • A
    $A + I$
  • ✓
    $A$
  • C
    $0$
  • D
    $2A$
✓

Answer

Correct option: B.
$A$
$A^2=1$
$A^{-1} A^2=A^{-1} I$
$A=A^{-1}$

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