Number 41

1 200 mil 41. A manufacturer of athletic footwear finds that the sales of their ZipStride brand running shoes is a function f(p) of the selling price p (in dollars) for a pair of shoes. Suppose that f(120) = 9000 pairs of shoes and f (120) = -60 pairs of shoes per dollar. The revenue that the manufacturer will re- ceive for selling f(p) pairs of shoes at p dollars per pair is hard a R(p) = p . f(p). Find R'(120). What impact would a small increase in price have on the manufacturer's revenue