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MHT CET202124 Sep 2021Evening ShiftMathematicsMatricesActual

If A= [ array ccc 1 & 2 & 3 -1 & 1 & 2 1 & 2 & 4 array ] , and A( adj A)=k I , then the value of (k+1)^4 is

Options

  1. A256
  2. B81
  3. C16
  4. D625

Correct answer

A. 256

Step-by-step solution

|A|= | array ccc 1 & 2 & 3 -1 & 1 & 2 1 & 2 & 4 array |=1(0)-2(-6)+3(-3)=3 We know that A ( adj A )=| A | I aligned & A ( adj A )=3 I k =3 & ( k +1)^4=(3+1)^4=256 aligned

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