OCR MEI Further Pure Core Specimen — Question 13

Exam BoardOCR MEI
ModuleFurther Pure Core (Further Pure Core)
SessionSpecimen
Topic3x3 Matrices

13 Matrix \(\mathbf { M }\) is given by \(\mathbf { M } = \left( \begin{array} { c c c } k & 1 & - 5
2 & 3 & - 3
- 1 & 2 & 2 \end{array} \right)\), where \(k\) is a constant.
  1. Show that \(\operatorname { det } \mathbf { M } = 12 ( k - 3 )\).
  2. Find a solution of the following simultaneous equations for which \(x \neq z\). $$\begin{aligned} 4 x ^ { 2 } + y ^ { 2 } - 5 z ^ { 2 } & = 6
    2 x ^ { 2 } + 3 y ^ { 2 } - 3 z ^ { 2 } & = 6
    - x ^ { 2 } + 2 y ^ { 2 } + 2 z ^ { 2 } & = - 6 \end{aligned}$$
  3. (A) Verify that the point ( \(2,0,1\) ) lies on each of the following three planes. $$\begin{aligned} 3 x + y - 5 z & = 1
    2 x + 3 y - 3 z & = 1
    - x + 2 y + 2 z & = 0 \end{aligned}$$ (B) Describe how the three planes in part (iii) (A) are arranged in 3-D space. Give reasons for your answer.
  4. Find the values of \(k\) for which the transformation represented by \(\mathbf { M }\) has a volume scale factor of 6 .