3 The matrix \(\mathbf { A }\) is given by \(\mathbf { A } = \left( \begin{array} { l l } 2 & a
0 & 1 \end{array} \right)\), where \(a\) is a constant.
- Find \(\mathbf { A } ^ { - 1 }\).
The matrix \(\mathbf { B }\) is given by \(\mathbf { B } = \left( \begin{array} { l l } 2 & a
4 & 1 \end{array} \right)\). - Given that \(\mathbf { P A } = \mathbf { B }\), find the matrix \(\mathbf { P }\).