COMEDK2019MathematicsMatrices
If A= [ array ll 1 & 2 3 & 4 array ] , then A⁻¹=
Options
- A-1 2 [ array cc 4 & -2 -3 & 1 array ]
- B1 2 [ array cc 4 & -2 -3 & 1 array ]
- C[ array cc -2 & 4 1 & 3 array ]
- D[ array ll 2 & 4 1 & 3 array ]
Correct answer
A. -1 2 [ array cc 4 & -2 -3 & 1 array ]
Step-by-step solution
If A= [ array ll a & b c & d array ] , then A⁻¹= 1 |A| [ array cc d & -b -c & a array ] So, if A= [ array ll 1 & 2 3 & 4 array ] , then array r A⁻¹= 1 4-6 [ array cc 4 & -2 -3 & 1 array ] =- 1 2 [ array cc 4 & -2 -3 & 1 array ] array