Kunze Linear Algebra · Problem 5.4.1

Determinants

Mathematics — Methods · classical-adjoint-inverse

Problem

Use the classical adjoint formula to compute the inverses of each of the following

3 \times 3

real matrices.

\begin{bmatrix}-2 & 3 & 2\\ 6 & 0 & 3\\ 4 & 1 & -1\end{bmatrix}, \qquad \begin{bmatrix}\cos\theta & 0 & -\sin\theta\\ 0 & 1 & 0\\ \sin\theta & 0 & \cos\theta\end{bmatrix}