9. \(f ( x ) = x ^ { 3 } - 4 x ^ { 2 } - 3 x + 18\).
- Show that \(( x - 3 )\) is a factor of \(\mathrm { f } ( x )\).
- Fully factorise \(\mathrm { f } ( x )\).
- Using your answer to part (b), write down the coordinates of one of the turning points of the curve \(y = \mathrm { f } ( x )\) and give a reason for your answer.
- Using differentiation, find the \(x\)-coordinate of the other turning point of the curve \(y = \mathrm { f } ( x )\).