9 The equation of a curve is \(y = 12 x - 4 x ^ { \frac { 3 } { 2 } }\).
- State the coordinates of the intersection of the curve with the \(y\)-axis.
- Find the value of \(y\) when \(x = 9\).
- Determine the coordinates of the stationary point.
- Sketch the curve, giving the coordinates of the stationary point and of any intercepts with the axes.