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MHT CET202019 Oct 2020Evening ShiftMathematicsMatricesActual

If A= [ array ll 4 & 5 2 & 1 array ] and A²-5 A-6 I=0 , then A⁻¹=

Options

  1. A1 6 [ array cc -1 & 5 2 & 4 array ]
  2. B1 6 [ array cc -1 & 5 -2 & -4 array ]
  3. C1 6 [ array cc -1 & 5 2 & -4 array ]
  4. D1 6 [ array cc 1 & 5 2 & -4 array ]

Correct answer

C. 1 6 [ array cc -1 & 5 2 & -4 array ]

Step-by-step solution

(D) array l A= [ array cc 4 & 5 2 & 1 array ] |A|=4-10--6 and ( adj A)- [ array cc 1 & 5 -2 & 4 array ] A⁻¹=- 1 6 [ array cc 1 & -5 -2 & 4 array ]= 1 6 [ array cc -1 & 5 2 & -4 array ] array

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