OCR FP1 2012 June — Question 10

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Year2012
SessionJune
Topic3x3 Matrices

10 The matrix \(\mathbf { D }\) is given by \(\mathbf { D } = \left( \begin{array} { r r r } a & 2 & - 1
2 & a & 1
1 & 1 & a \end{array} \right)\).
  1. Find the determinant of \(\mathbf { D }\) in terms of \(a\).
  2. Three simultaneous equations are shown below. $$\begin{array} { r } a x + 2 y - z = 0
    2 x + a y + z = a
    x + y + a z = a \end{array}$$ For each of the following values of \(a\), determine whether or not there is a unique solution. If the solution is not unique, determine whether the equations are consistent or inconsistent.
    (a) \(\quad a = 3\)
    (b) \(a = 2\)
    (c) \(\quad a = 0\) \section*{THERE ARE NO QUESTIONS WRITTEN ON THIS PAGE}