Edexcel F1 2021 October — Question 1 5 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2021
SessionOctober
Marks5
PaperDownload PDF ↗
TopicMatrices
TypeMatrix satisfying given equation
DifficultyStandard +0.3 This is a straightforward Further Maths matrix question requiring standard matrix inversion (using the 2×2 formula with determinant) followed by solving a matrix equation by equating corresponding elements. While it involves algebraic manipulation and is from Further Maths, the techniques are routine and the problem-solving demand is modest—slightly easier than average for A-level overall but typical for F1.
Spec4.03n Inverse 2x2 matrix4.03o Inverse 3x3 matrix

1. $$\mathbf { A } = \left( \begin{array} { r r } 3 & a \\ - 2 & - 2 \end{array} \right)$$ where \(a\) is a non-zero constant and \(a \neq 3\)
  1. Determine \(\mathbf { A } ^ { - 1 }\) giving your answer in terms of \(a\). Given that \(\mathbf { A } + \mathbf { A } ^ { - 1 } = \mathbf { I }\) where \(\mathbf { I }\) is the \(2 \times 2\) identity matrix,
  2. determine the value of \(a\).

1.

$$\mathbf { A } = \left( \begin{array} { r r } 
3 & a \\
- 2 & - 2
\end{array} \right)$$

where $a$ is a non-zero constant and $a \neq 3$
\begin{enumerate}[label=(\alph*)]
\item Determine $\mathbf { A } ^ { - 1 }$ giving your answer in terms of $a$.

Given that $\mathbf { A } + \mathbf { A } ^ { - 1 } = \mathbf { I }$ where $\mathbf { I }$ is the $2 \times 2$ identity matrix,
\item determine the value of $a$.
\end{enumerate}

\hfill \mbox{\textit{Edexcel F1 2021 Q1 [5]}}