3. The matrix \(\mathbf { M }\) is defined by
$$\mathbf { M } = \left( \begin{array} { c c }
k + 5 & - 2
- 3 & k
\end{array} \right)$$
- Determine the values of \(k\) for which \(\mathbf { M }\) is singular.
Given that \(\mathbf { M }\) is non-singular,
- find \(\mathbf { M } ^ { - 1 }\) in terms of \(k\).