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MHT CET20228 Aug 2022Evening ShiftMathematicsMatricesActual

If A= [ array cc 2 & 3 -4 & 1 array ] , then adj (3 A^2+12 A ) is equal to

Options

  1. A[ array cc -21 & 63 84 & 0 array ]
  2. B[ array cc 21 & 63 84 & 0 array ]
  3. C[ array cc 21 & -63 84 & 0 array ]
  4. D[ array cc -21 & -63 84 & 0 array ]

Correct answer

D. [ array cc -21 & -63 84 & 0 array ]

Step-by-step solution

aligned & 3 A^2+12 A=3 [ array cc 2 & 3 -4 & 1 array ]^2+12 & =3 [ array cc -8 & 9 -12 & -11 array ]+12 [ array cc 2 & 3 -4 & 1 array ] & = [ array cc -24+24 & 27+36 -36-48 & -33+12 array ] & = [ array cc 0 & 63 -84 & -21 array ] & adj (3 A^2+12 A )= [ array cc -21 & -63 84 & 0 array ] aligned

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