Edexcel F1 2023 January — Question 1 5 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2023
SessionJanuary
Marks5
PaperDownload PDF ↗
TopicMatrices
TypeMatrix multiplication
DifficultyModerate -0.8 This is a straightforward matrix multiplication followed by a routine determinant calculation and solving a linear equation. Part (a) requires careful arithmetic with the parameter k, and part (b) involves computing a 2×2 determinant and solving for k. While it requires accuracy, it demands only direct application of standard techniques with no problem-solving insight, making it easier than average.
Spec4.03b Matrix operations: addition, multiplication, scalar4.03j Determinant 3x3: calculation

  1. Given that
$$\mathbf { A } = \left( \begin{array} { r r r } 2 & - 1 & 3 \\ - 2 & 3 & 0 \end{array} \right) \quad \text { and } \quad \mathbf { B } = \left( \begin{array} { r r } 1 & k \\ 0 & - 3 \\ 2 k & 2 \end{array} \right)$$ where \(k\) is a non-zero constant,
  1. determine the matrix \(\mathbf { A B }\)
  2. determine the value of \(k\) for which \(\operatorname { det } ( \mathbf { A B } ) = 0\)

\begin{enumerate}
  \item Given that
\end{enumerate}

$$\mathbf { A } = \left( \begin{array} { r r r } 
2 & - 1 & 3 \\
- 2 & 3 & 0
\end{array} \right) \quad \text { and } \quad \mathbf { B } = \left( \begin{array} { r r } 
1 & k \\
0 & - 3 \\
2 k & 2
\end{array} \right)$$

where $k$ is a non-zero constant,\\
(a) determine the matrix $\mathbf { A B }$\\
(b) determine the value of $k$ for which $\operatorname { det } ( \mathbf { A B } ) = 0$

\hfill \mbox{\textit{Edexcel F1 2023 Q1 [5]}}