| Exam Board | AQA |
|---|
| Module | Further Paper 2 (Further Paper 2) |
|---|
| Year | 2020 |
|---|
| Session | June |
|---|
| Topic | Matrices |
|---|
4 The matrices A and B are defined as follows:
$$\begin{aligned}
& \mathbf { A } = \left[ \begin{array} { l l }
x + 1 & 2
x + 2 & - 3
\end{array} \right]
& \mathbf { B } = \left[ \begin{array} { c c }
x - 4 & x - 2
0 & - 2
\end{array} \right]
\end{aligned}$$
Show that there is a value of \(x\) for which \(\mathbf { A B } = k \mathbf { I }\), where \(\mathbf { I }\) is the \(2 \times 2\) identity matrix and \(k\) is an integer to be found.