8. A curve has the equation
$$x ^ { 2 } - 4 x y + 2 y ^ { 2 } = 1$$
- Find an expression for \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in its simplest form in terms of \(x\) and \(y\).
- Show that the tangent to the curve at the point \(P ( 1,2 )\) has the equation
$$3 x - 2 y + 1 = 0$$
The tangent to the curve at the point \(Q\) is parallel to the tangent at \(P\).
- Find the coordinates of \(Q\).