1. The curve C is given by the equation y=mx^{3}-x^{2}+8x+2, for a constant m

A) find dy/dx

The point P lies on C, and has the x-value 5

The normal to C at P is parallel to the line given by the equation y+4x-3=0.

B)find the gradient of the curve at C at P.

Hence find:

C) (I) the value of m,

(ii) the y-value at p.

For A) i got:

dy/dx=3mx^{2}-x+8

I'm not really sure how to carry on with it now any help would be brilliant

Thanks.