6 The matrix \(\mathbf { C }\) is given by \(\mathbf { C } = \left( \begin{array} { l l } 1 & 2
3 & 8 \end{array} \right)\).
- Find \(\mathbf { C } ^ { - 1 }\).
- Given that \(\mathbf { C } = \mathbf { A B }\), where \(\mathbf { A } = \left( \begin{array} { l l } 2 & 1
1 & 3 \end{array} \right)\), find \(\mathbf { B } ^ { - 1 }\).