- Given that \(k\) is a real number and that
$$\mathbf { A } = \left( \begin{array} { c c }
1 + k & k
k & 1 - k
\end{array} \right)$$
find the exact values of \(k\) for which \(\mathbf { A }\) is a singular matrix. Give your answers in their simplest form.
(3)