All work must be shown for credit. Answers provided without supporting work will be awarded minimal credit. Let f(x) = 24 - 4x2. a. Find all the points where f has horizontal tangents. b. Find an equation of the tangent line at x = 1. c. Find an equation of the normal line at x = 1. (remember the normal line is the line perpendicular to the tangent line at the x value)