Answer: ad − bc.
- A ad − bc
- B ab − cd
- C ad + bc
- D ac − bd
Correct answer: A. ad − bc
Explanation: For a 2×2 matrix the determinant is (top-left × bottom-right) − (top-right × bottom-left) = ad − bc.
Concept context
Evaluation of determinants, cofactors, adjoint, inverse of matrix, Cramer's rule and area applications. Always in board and JEE.