9. The curve \(C\) has equation \(y = \mathrm { f } ( x )\). Given that \(\frac { \mathrm { d } y } { \mathrm {~d} x } = 3 x ^ { 2 } - 20 x + 29\) and that \(C\) passes through the point \(P ( 2,6 )\),
- find \(y\) in terms of \(x\).
- Verify that \(C\) passes through the point \(( 4,0 )\).
- Find an equation of the tangent to \(C\) at \(P\).
The tangent to \(C\) at the point \(Q\) is parallel to the tangent at \(P\).
- Calculate the exact \(x\)-coordinate of \(Q\).