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MHT CET202122 Sep 2021Evening ShiftMathematicsMatricesActual

For an invertible matrix A , if A( adj A)= [ array cc 20 & 0 0 & 20 array ] , then |A|=

Options

  1. A-200
  2. B200
  3. C-2
  4. D20

Correct answer

D. 20

Step-by-step solution

aligned & We have A ( adj A )= [ array cc 20 & 0 0 & 20 array ] & | A || adj A |= [ array cc 20 & 0 0 & 20 array ] | A | (| A |²⁻¹ )=400 (| A |)^2=(20)^2 & | A |=20 aligned

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