CAIE FP1 2010 June — Question 12 OR

Exam BoardCAIE
ModuleFP1 (Further Pure Mathematics 1)
Year2010
SessionJune
Topic3x3 Matrices

The linear transformation \(\mathrm { T } : \mathbb { R } ^ { 4 } \rightarrow \mathbb { R } ^ { 4 }\) is represented by the matrix \(\mathbf { M } = \left( \begin{array} { r r r r } 1 & 1 & 5 & 7
3 & 9 & 17 & 25
1 & 7 & 7 & 11
3 & 6 & 16 & 23 \end{array} \right)\).
  1. In either order,
    (a) show that the dimension of \(R\), the range space of T , is equal to 2 ,
    (b) obtain a basis for \(R\).
  2. Show that the vector \(\left( \begin{array} { r } 1
    - 15
    - 17
    - 6 \end{array} \right)\) belongs to \(R\).
  3. It is given that \(\left\{ \mathbf { e } _ { 1 } , \mathbf { e } _ { 2 } \right\}\) is a basis for the null space of T , where \(\mathbf { e } _ { 1 } = \left( \begin{array} { r } 14
    1
    - 3
    0 \end{array} \right)\) and \(\mathbf { e } _ { 2 } = \left( \begin{array} { r } 19
    2
    0
    - 3 \end{array} \right)\). Show that, for all \(\lambda\) and \(\mu\), $$\mathbf { x } = \left( \begin{array} { r } 4
    - 3
    0
    0 \end{array} \right) + \lambda \mathbf { e } _ { 1 } + \mu \mathbf { e } _ { 2 }$$ is a solution of $$\mathbf { M x } = \left( \begin{array} { r } 1
    - 15
    - 17
    - 6 \end{array} \right)$$
  4. Hence find a solution of \(( * )\) of the form \(\left( \begin{array} { c } \alpha
    0
    \gamma
    \delta \end{array} \right)\).