Consider the function f(x) = -2 x^2 + 9 x + 11

(a) find [f(x+h) - f(x)]/h in the form __x+ __h+___

(I found -4x-2h+9, which was correct)

(b) Using the result of (a), find the derivative of f at x.

(I found -4x+9, also correct)

***(c) Find the point of intersection of the two tangent lines to the parabola y = -2x^2 + 9x + 11 at the points (3,20) and (-4,-57)

How do i do this? What are the two tangent lines they are talking about?

I don't know where to start on this bad boy, thanks so much