1 The matrices \(\mathbf { A }\) and \(\mathbf { B }\) are given by
$$\mathbf { A } = \left[ \begin{array} { l l }
2 & 1
3 & 8
\end{array} \right] , \quad \mathbf { B } = \left[ \begin{array} { l l }
1 & 2
3 & 4
\end{array} \right]$$
The matrix \(\mathbf { M } = \mathbf { A } - 2 \mathbf { B }\).
- Show that \(\mathbf { M } = n \left[ \begin{array} { r r } 0 & - 1
- 1 & 0 \end{array} \right]\), where \(n\) is a positive integer.
(2 marks) - The matrix \(\mathbf { M }\) represents a combination of an enlargement of scale factor \(p\) and a reflection in a line \(L\). State the value of \(p\) and write down the equation of \(L\).
- Show that
$$\mathbf { M } ^ { 2 } = q \mathbf { I }$$
where \(q\) is an integer and \(\mathbf { I }\) is the \(2 \times 2\) identity matrix.