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Let   .The only correct statement about the matrix A is

  • Option 1)

    A^{-1}  does not exist

  • Option 2)

    A=(-1)I,where\, I is a unit matrix

  • Option 3)

    A is a zero matrix

  • Option 4)

    A^{2}=I

 

Answers (2)

best_answer

As we learnt in 

Multiplication of matrices -

-

 

 A= \begin{bmatrix} 0&0 &-1 \\ 0& -1 &0 \\ -1&0 &0 \end{bmatrix}

A^{2}= \begin{bmatrix} 0&0 &-1 \\ 0& -1 &0 \\ -1&0 &0 \end{bmatrix} \begin{bmatrix} 0&0 &-1 \\ 0& -1 &0 \\ -1&0 &0 \end{bmatrix}= \begin{bmatrix} 1&0 &0 \\ 0& 1 &0 \\ 0&0 &1 \end{bmatrix}=I

 


Option 1)

A^{-1}  does not exist

Incorrect option

Option 2)

A=(-1)I,where\, I is a unit matrix

Incorrect option

Option 3)

A is a zero matrix

Incorrect option

Option 4)

A^{2}=I

Correct option

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