AQA FP1 2008 January — Question 6

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2008
SessionJanuary
TopicLinear transformations

6 The matrix \(\mathbf { M }\) is defined by $$\mathbf { M } = \left[ \begin{array} { c c } \sqrt { 3 } & 3
3 & - \sqrt { 3 } \end{array} \right]$$
    1. Show that $$\mathbf { M } ^ { 2 } = p \mathbf { I }$$ where \(p\) is an integer and \(\mathbf { I }\) is the \(2 \times 2\) identity matrix.
    2. Show that the matrix \(\mathbf { M }\) can be written in the form $$q \left[ \begin{array} { c c } \cos 60 ^ { \circ } & \sin 60 ^ { \circ }
      \sin 60 ^ { \circ } & - \cos 60 ^ { \circ } \end{array} \right]$$ where \(q\) is a real number. Give the value of \(q\) in surd form.
  1. The matrix \(\mathbf { M }\) represents a combination of an enlargement and a reflection. Find:
    1. the scale factor of the enlargement;
    2. the equation of the mirror line of the reflection.
  2. Describe fully the geometrical transformation represented by \(\mathbf { M } ^ { 4 }\).