Question

Let A be 2 x 2 matrix.Statement I `adj (adj A) = A` Statement II `|adj A| = A`
A. Statement 1 is true, statement 2 is true, statement 2 is a correct explanation for statement 1.
B. Statement 1 is true, statement 2 is true, statement 2 is a correct explanation for statement 1.
C. Statement 1 is true, statement 2 is false.
D. Statement 1 is false, statement 2 is true.

Answer 1

Correct Answer - B
`|"adj A"|=|A|^(n-1)=|A|^(2-1)=|A|`
adj (adj A)`=|A|^(n-2) A=|A|^(0) A=A`
Thus both statements are true, but statement 2 is not correct explanation of statement 1.