CAIE Further Paper 1 2022 June — Question 5

Exam BoardCAIE
ModuleFurther Paper 1 (Further Paper 1)
Year2022
SessionJune
TopicProof by induction

5 Let \(\mathbf { A } = \left( \begin{array} { l l } 1 & a
0 & 1 \end{array} \right)\), where \(a\) is a positive constant.
  1. State the type of the geometrical transformation in the \(x - y\) plane represented by \(\mathbf { A }\).
  2. Prove by mathematical induction that, for all positive integers \(n\), $$\mathbf { A } ^ { \mathrm { n } } = \left( \begin{array} { c c } 1 & \mathrm { na }
    0 & 1 \end{array} \right)$$ Let \(\mathbf { B } = \left( \begin{array} { c c } b & b
    a ^ { - 1 } & a ^ { - 1 } \end{array} \right)\), where \(b\) is a positive constant.
  3. Find the equations of the invariant lines, through the origin, of the transformation in the \(x - y\) plane represented by \(\mathbf { A } ^ { n } \mathbf { B }\).