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Home  >>  JEEMAIN and AIPMT  >>  Mathematics  >>  Class12  >>  Matrices
0 votes

If $A$ is a square matrix such that $A^2=I$ then $A^{-1}$ is equal to

$(a)\;A+I\qquad(b)\;A\qquad(c)\;0\qquad(d)\;2A$

Can you answer this question?
 
 

1 Answer

0 votes
$A^2=I$
$\Rightarrow A^2A^{-1}=IA^{-1}$
$\Rightarrow A=A^{-1}$
Hence (b) is the correct answer.
answered Nov 21, 2013 by sreemathi.v
 

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