9
\end{array} \right) + t \left( \begin{array} { c }
2
- 3
1
\end{array} \right)$$
(ii) Show that lines \(l _ { 1 }\) and \(l _ { 2 }\) do not intersect.
(iii) Find the position vector of the point \(C\) on \(l _ { 2 }\) such that \(\angle A B C = 90 ^ { \circ }\).
8. \(f ( x ) = \frac { 5 - 8 x } { ( 1 + 2 x ) ( 1 - x ) ^ { 2 } }\).
- Express \(\mathrm { f } ( x )\) in partial fractions.
- Find the series expansion of \(\mathrm { f } ( x )\) in ascending powers of \(x\) up to and including the term in \(x ^ { 3 }\), simplifying each coefficient.
- State the set of values of \(x\) for which your expansion is valid.