Answer: [[d,-b],[-c,a]].
- A [[d,-b],[-c,a]]
- B [[d,b],[c,a]]
- C [[-d,b],[c,-a]]
- D [[a,c],[b,d]]
Correct answer: A. [[d,-b],[-c,a]]
Explanation: For [[a,b],[c,d]], swap a and d, and negate b and c: adj(A) = [[d,-b],[-c,a]].
Concept context
Evaluation of determinants, cofactors, adjoint, inverse of matrix, Cramer's rule and area applications. Always in board and JEE.