AQA Further AS Paper 1 2020 June — Question 4 2 marks

Exam BoardAQA
ModuleFurther AS Paper 1 (Further AS Paper 1)
Year2020
SessionJune
Marks2
TopicMatrices

4 The matrices \(\mathbf { A }\) and \(\mathbf { B }\) are such that $$\mathbf { A } = \left[ \begin{array} { c c c } 2 & a & 3
0 & - 2 & 1 \end{array} \right] \quad \text { and } \quad \mathbf { B } = \left[ \begin{array} { c c } 1 & - 3
- 2 & 4 a
0 & 5 \end{array} \right]$$ 4
  1. Find the product \(\mathbf { A B }\) in terms of \(a\).
    [0pt] [2 marks]
    4
  2. Find the determinant of \(\mathbf { A B }\) in terms of \(a\).
    \includegraphics[max width=\textwidth, alt={}, center]{86aa9e6f-261c-40d4-8271-a0dc560d8a72-04_31_31_513_367}
    "
    □ \(\quad \mathbf { A } = \left[ \begin{array} { c c c } 2 & a & 3
    0 & - 2 & 1 \end{array} \right]\) and \(\quad \mathbf { B } = \left[ \begin{array} { c c } 1 & - 3
    - 2 & 4 a
    0 & 5 \end{array} \right]\)
    \(\mathbf { 4 }\) (a) Find the product \(\mathbf { A B }\) in terms of \(a\). 4
  3. Show that \(\mathbf { A B }\) is singular when \(a = - 1\)