11. A curve is defined parametrically by
$$x = 2 \theta + \sin 2 \theta , \quad y = 1 + \cos 2 \theta$$
- Show that the gradient of the curve at the point with parameter \(\theta\) is \(- \tan \theta\).
- Find the equation of the tangent to the curve at the point where \(\theta = \frac { \pi } { 4 }\).