If A= bmatrix 2 & &0 -2 & &0 -1&1&1 bmatrix , then what is A(adjA) equal to? where I is the identity matrix.

NDA 2022 Mathematics question

If , then what is equal to? where is the identity matrix.

Answer: (D)

. Expanding along the third column: . Hence .

Question ID VK-029296