Consider the function f(x) = x +4.5x 12x-1. Its derivative is f'(x) = 3x^2+9x-12 Its second derivative is f"(x)=6x+9 help (formulas) The graph that correctly displays f(x) (in black) and f"(x) (in orange) is OA B. A. E D. Using the graphs of f and f", indicate where f is concave up and concave down. Enter D f is concave up on (-5,-2) f is concave down on (-2,infinty) help (intervals).