Methods of integration help!

Im in year ten at school and our teacher has given us this homework question that i dont understand and dont know how to start :( would anyone be able to help me with how to do it

The sanctuary for the endangered bunyip is located between two straight fences and a river. A reference point is established at *Q* where two of the fences intersect at right angles, one running due north from *Q* and the other due east.

An aerial survey undertaken shows that in the relevant area, the river follows a path closely approximating the curve: *N* = *E*3 – 6*E*2 + 5*E* + 12 where *N* and *E* are measured in km along the north and east running fences respectively.

a) Draw an accurate graph of the sanctuary, listing all points of intersection. Prove that these points are accurate. Show all working.