If $A \text { is nonsingular, then }\left(A^{T}\right)^{-1}=\left(A^{-1}\right)^{T}$$\begin{array}{l}{\text { (a) Verify this theorem for } 2 \times 2 \text { matrices. }} \\ {\text { (b) Prove the theorem for any } n \times n \text { matrix. [Hint. You }} \\ {\text { might wish to use the property from Exercise } 8.4 .15(\mathrm{b}) .}\end{array}$