[video]http://www.examsolutions.net/maths-revision/further-maths/coordinate-geometry/parabola/tangent-normal/cartesian/example-1.php[/video]
In this video he uses implicit diff which i don't know how to do so i just square rooted both sides and used c1 diff from there to get tangents and normals but the implicit diff method gives the tangent and normal on the point (9,-12) so do i need to include all the tangents and normals?