a Use six rectangles to find estimates of each type for the area under the given graph of f from x=0 to x=12. i L6 sample points are left endpoints ii R6, sample points are right endpoints iii M6 sample points are midpoints b Is L6 an underestimate or overestimate of the true area? c Is R6 an underestimate or overestimate of the true area? d Which of the numbers L6, R6, or M6 gives the best estimate? Explain.