6 A curve \(C\) has polar equation
$$r ^ { 2 } \sin 2 \theta = 8$$
- Find the cartesian equation of \(C\) in the form \(y = \mathrm { f } ( x )\).
- Sketch the curve \(C\).
- The line with polar equation \(r = 2 \sec \theta\) intersects \(C\) at the point \(A\). Find the polar coordinates of \(A\).