FIND A, B, C, D, and y

Let f(x) = x2+ 6x. (A) Find the slope of the secant line joining (3, f(3)) and (8; f(8)). Slope of secant line = (B) Find the slope of the secant line joining (6, f(6)) and (6 + h, f(6 + h)). Slope of secant line = (C) Find the slope of the tangent line at (6, f(6)). Slope of tangent line = (D) Find the equation of the tangent line at (6, f(6))