Please help, this question is killing me!!

Hello, I have been working on this question for a couple of days now, have no idea about it, please help...

A polynomial function is defined by f(x) = x^3 + 2x^2 - 5x - 6

a) Deteremine the coordiantes of four points on the graph of f(x). choose the points so the tangent line at each point is a side of a parallelogram.

b) Determine the equations of the four tangents lines in part a.

c) sketch a graph of f(x) and the tangent lines. also clearly mark the parallelogram on this graph.

Pleas help... thanx in advance