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# Engineering

If    is the adjoint of a 3 x 3  matrix A and \left | A \right | = 4,then \alpha is equal to :

  • Option 1)

    0

  • Option 2)

    4

  • Option 3)

    11

  • Option 4)

    5

 

Answers (2)
N neha
G gaurav

As we have learned

Property of adjoint of A -

\left | adj A \right |=\left | A \right |^{n-1}  

- wherein

adj A denotes adjoint of A and  \left |A \right |  denotes determinant  of A and n is the order of the matrix

 

|adj \; \; A| = |A|^{3-1}

\Rightarrow |adj \; \; A| =4^2=16

\Rightarrow 0-\alpha (-2)+3(-2)=16

\Rightarrow 2\alpha -6 = 16

\Rightarrow \alpha = 11

 

 

 

 

 

 

 


Option 1)

0

Option 2)

4

Option 3)

11

Option 4)

5

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