Answer: det(A) is not zero.
- A det(A) = 0
- B A is singular
- C B = 0
- D det(A) is not zero
Correct answer: D. det(A) is not zero
Explanation: A unique solution exists when the coefficient matrix A is non-singular, i.e., det(A) is not zero.
Concept context
Evaluation of determinants, cofactors, adjoint, inverse of matrix, Cramer's rule and area applications. Always in board and JEE.