Determinants

Let \(A = \begin{bmatrix} 1 & 2 & 1 \\ 2 & 3 & 1 \\ 1 & 1 & 5 \end{bmatrix}\). Verify that: (i) \([\text{adj } A]^{-1} = \text{adj}(A^{-1})\) (ii) \((A^{-1})^{-1} = A\)