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MHT CET202012 Oct 2020Morning ShiftMathematicsMatricesActual

If A= [ array cc 2 & -1 -1 & 2 array ] , such that A²-4 A+3 I=0 , then A⁻¹=

Options

  1. A-1 3 [ array ll 2 & 1 1 & 2 array ]
  2. B-1 3 [ array cc 2 & -1 -1 & 2 array ]
  3. C1 3 [ array cc -2 & -1 1 & -2 array ]
  4. D1 3 [ array ll 2 & 1 1 & 2 array ]

Correct answer

D. 1 3 [ array ll 2 & 1 1 & 2 array ]

Step-by-step solution

A= [ array cc 2 & -1 -1 & 2 array ] |A|=4-1=3 and ( adj A)= [ array ll 2 & 1 1 & 2 array ] A⁻¹ = 1 3 [ array ll 2 & 1 1 & 2 array ]

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