5 The parametric equations of a curve are
$$x = \ln ( \tan t ) , \quad y = \sin ^ { 2 } t$$
where \(0 < t < \frac { 1 } { 2 } \pi\).
- Express \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(t\).
- Find the equation of the tangent to the curve at the point where \(x = 0\).