MHT CET202121 Sep 2021Evening ShiftMathematicsMatricesActual
If A= [ array lll 0 & 1 & 2 1 & 2 & 3 3 & 1 & 1 array ] , then A⁻¹=
Options
- A( 1 2 ) [ array lll 0 & 1 & 2 3 & 2 & 1 4 & 2 & 3 array ]
- B[ array ccc 1 2 & -1 2 & 1 2 -4 & 3 & -1 5 2 & -3 2 & 1 2 array ]
- C[ array ccc 1 2 & -1 & 5 2 1 & -6 & 3 1 & 2 & -1 array ]
- D( 1 2 ) [ array ccc 1 & -1 & -1 -8 & 6 & -2 5 & -3 & 1 array ]
Correct answer
B. [ array ccc 1 2 & -1 2 & 1 2 -4 & 3 & -1 5 2 & -3 2 & 1 2 array ]
Step-by-step solution
aligned & [ array lll 0 & 1 & 2 1 & 2 & 3 3 & 1 & 1 array ] A ⁻¹= [ array lll 1 & 0 & 0 0 & 1 & 0 0 & 0 & 1 array ] & R ₁ R ₁+ R ₂ and R ₃ R ₃-3 R ₂ & [ array ccc 1 & 3 & 5 1 & 2 & 3 0 & -5 & -8 array ] A ⁻¹= [ array ccc 1 & 1 & 0 0 & 1 & 0 0 & -3 & 1 array ] & R ₂ R ₂- R ₁ & [ array ccc 1 & 3 & 5 0 & -1 & -2 0 & -5 & -8 array ] A ⁻¹= [ array ccc 1 & 1 & 0 -1 & 0 & 0 0 & -3 & 1 array ] & R ₁ R ₁+3 R ₂ and R ₃ R ₃-5 R ₂ & [ array ccc 1 & 0 & -1 0 & -1 & -2 0 & 0 & 2 array ] A ⁻¹= [ array ccc -2 & 1 & 0 -1 & 0 & 0 5