(9) a) Sketch the function f(x)=x-4 from x = -2 to x = 10. b) Approximate the signed area for f(x) on [-2, 10] by using right hand sums with n = 3. c) Is your answer in b) an overestimate or an underestimate of the actual signed area? d) On the graph that you drew in part a), sketch the rectangles that you used in part b).