- The curve \(C\) has equation
$$81 y ^ { 3 } + 64 x ^ { 2 } y + 256 x = 0$$
- Find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(x\) and \(y\).
- Hence find the coordinates of the points on \(C\) where \(\frac { \mathrm { d } y } { \mathrm {~d} x } = 0\)