15. [-I3 Points] HARMATHAP12 9.5.031. PRACTICE ANOTHER Consider the following. f(x) = (x2 + 4x + 4)(x 7) (a) Flnd the derivative of the function, and check your work by graphing both your calculated derivative and the numerical derivative of the function. f'(X) = 07) Use your graph of the derivative to find points where the original function has horizontal tangent lines. (Enter your answers as a comma-separated list.) (c) Use a graphing calculator to graph the function and indicate the points found in part (b) on the graph. Y Y Need Help? Show My Work (Mun-I) o