4 A curve has parametric equations
$$x = 2 + t ^ { 2 } , \quad y = 4 t$$
- Find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(t\).
- Find the equation of the normal at the point where \(t = 4\), giving your answer in the form \(y = m x + c\).
- Find a cartesian equation of the curve.