Practicing Success
Let A be a 2 × 2 matrix. Statement-1: $adj (adj\, A) = A$ Statement-2: $|adj\, A|=|A|$ |
Statement-1 is True, Statement-2 is true; Statement-2 is a correct explanation for Statement-1. Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1. Statement-1 is True, Statement-2 is False. Statement-1 is False, Statement-2 is True. |
Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1. |
For any square matrix A of order n, we have $|adj\, A|=|A|^{n-1}$ and $adj (adj\, A) =|A|^{n-2} A$ For a 2 × 2 matrix, we have n = 2. $|adj\, A|=|A|$ and $adj (adj\, A) = A$ Also, $adj (adj\, A) =|A|^{n-2} A$ is obtained by replacing A by $adj\, A$ in the relation $A (adj\, A) =|A|I_n$ Hence, both the statements are true. But, statement-2 is the correct explanation for statement-1. |