OCR MEI FP2 2010 June — Question 3

Exam BoardOCR MEI
ModuleFP2 (Further Pure Mathematics 2)
Year2010
SessionJune
TopicInvariant lines and eigenvalues and vectors

3
    1. A \(3 \times 3\) matrix \(\mathbf { M }\) has characteristic equation $$2 \lambda ^ { 3 } + \lambda ^ { 2 } - 13 \lambda + 6 = 0$$ Show that \(\lambda = 2\) is an eigenvalue of \(\mathbf { M }\). Find the other eigenvalues.
    2. An eigenvector corresponding to \(\lambda = 2\) is \(\left( \begin{array} { r } 3
      - 3
      1 \end{array} \right)\). Evaluate \(\mathbf { M } \left( \begin{array} { r } 3
      - 3
      1 \end{array} \right)\) and \(\mathbf { M } ^ { 2 } \left( \begin{array} { r } 1
      - 1
      \frac { 1 } { 3 } \end{array} \right)\).
      Solve the equation \(\mathbf { M } \left( \begin{array} { l } x
      y
      z \end{array} \right) = \left( \begin{array} { r } 3
      - 3
      1 \end{array} \right)\).
    3. Find constants \(A , B , C\) such that $$\mathbf { M } ^ { 4 } = A \mathbf { M } ^ { 2 } + B \mathbf { M } + C \mathbf { I }$$
  1. A \(2 \times 2\) matrix \(\mathbf { N }\) has eigenvalues -1 and 2, with eigenvectors \(\binom { 1 } { 2 }\) and \(\binom { - 1 } { 1 }\) respectively. Find \(\mathbf { N }\). Section B (18 marks)