AQA FP1 2014 June — Question 7 10 marks

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2014
SessionJune
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicLinear transformations
TypeWrite down transformation matrix
DifficultyModerate -0.3 This is a standard FP1 matrices question testing routine transformations and matrix properties. Parts (a)-(b) require direct recall of standard transformation matrices (reflection in y=-x and stretch), part (c) is straightforward matrix multiplication, and part (d) involves computing A² and recognizing the form of a combined transformation. While part (d)(ii) requires identifying the enlargement factor and reflection line from matrix entries, this follows a standard method taught in FP1. The question is slightly easier than average A-level difficulty due to its structured, methodical nature with clear signposting.
Spec4.03b Matrix operations: addition, multiplication, scalar4.03d Linear transformations 2D: reflection, rotation, enlargement, shear4.03e Successive transformations: matrix products4.03h Determinant 2x2: calculation4.03i Determinant: area scale factor and orientation

  1. Write down the \(2 \times 2\) matrix corresponding to each of the following transformations:
    1. a reflection in the line \(y = -x\); [1 mark]
    2. a stretch parallel to the \(y\)-axis of scale factor \(7\). [1 mark]
  2. Hence find the matrix corresponding to the combined transformation of a reflection in the line \(y = -x\) followed by a stretch parallel to the \(y\)-axis of scale factor \(7\). [2 marks]
  3. The matrix \(\mathbf{A}\) is defined by \(\mathbf{A} = \begin{bmatrix} -3 & -\sqrt{3} \\ -\sqrt{3} & 3 \end{bmatrix}\).
    1. Show that \(\mathbf{A}^2 = k\mathbf{I}\), where \(k\) is a constant and \(\mathbf{I}\) is the \(2 \times 2\) identity matrix. [1 mark]
    2. Show that the matrix \(\mathbf{A}\) corresponds to a combination of an enlargement and a reflection. State the scale factor of the enlargement and state the equation of the line of reflection in the form \(y = (\tan \theta)x\). [5 marks]

Question 7:
7
Question 7:
7
\begin{enumerate}[label=(\alph*)]
\item Write down the $2 \times 2$ matrix corresponding to each of the following transformations:
\begin{enumerate}[label=(\roman*)]
\item a reflection in the line $y = -x$; [1 mark]

\item a stretch parallel to the $y$-axis of scale factor $7$. [1 mark]
\end{enumerate}

\item Hence find the matrix corresponding to the combined transformation of a reflection in the line $y = -x$ followed by a stretch parallel to the $y$-axis of scale factor $7$. [2 marks]

\item The matrix $\mathbf{A}$ is defined by $\mathbf{A} = \begin{bmatrix} -3 & -\sqrt{3} \\ -\sqrt{3} & 3 \end{bmatrix}$.
\begin{enumerate}[label=(\roman*)]
\item Show that $\mathbf{A}^2 = k\mathbf{I}$, where $k$ is a constant and $\mathbf{I}$ is the $2 \times 2$ identity matrix. [1 mark]

\item Show that the matrix $\mathbf{A}$ corresponds to a combination of an enlargement and a reflection. State the scale factor of the enlargement and state the equation of the line of reflection in the form $y = (\tan \theta)x$. [5 marks]
\end{enumerate}
\end{enumerate}

\hfill \mbox{\textit{AQA FP1 2014 Q7 [10]}}