OCR Further Pure Core 2 2020 November — Question 7

Exam BoardOCR
ModuleFurther Pure Core 2 (Further Pure Core 2)
Year2020
SessionNovember
TopicInvariant lines and eigenvalues and vectors

7 The matrix \(\mathbf { A }\) is given by \(\mathbf { A } = \left( \begin{array} { r r } 0.6 & 2.4
- 0.8 & 1.8 \end{array} \right)\).
  1. Find \(\operatorname { det } \mathbf { A }\). The matrix A represents a stretch parallel to one of the coordinate axes followed by a rotation about the origin.
  2. By considering the determinants of these transformations, determine the scale factor of the stretch.
  3. Explain whether the stretch is parallel to the \(x\)-axis or the \(y\)-axis, justifying your answer.
  4. Find the angle of rotation.