Hello,

I am trying to solve for the x's for y=ax^3+bx^2+cx+d.

It cuts the y-axis at (0,30). The gradient at this point is -1.

The gradient where x=1, is -17 and the f ``(x) at this point is -10.

I s.t the coordinates given; set f `(x) =-1 and

f ``(x)=-10.

I think d=30 and c=-1.

So I need to solve for a,b.

I didn't think solving for x would be this tricky? What have I missed?