Page of4 O ZOOM + l) The function P(x) = 2x2 +550x 6500 gives the prot when X units of a certain product are sold. Find the following parts and don't forget to write the unit. In each part, please briey explain your reasoning. If you don't explain you will not receive any credit. a. The prot when 85 units are sold. b. What is the meaning of average prot? Find the average prot per unit when 85 units are sold. c. The rate that prot is changing when exactly 85 units are sold. Page of4 O ZOOM + C. The rate that prot is changing when exactly 85 units are sold. d. The rate that prot changes on average when the number of units sold rises from 85 to l 5 0. e. The number of units sold when profit stops increasing and starts decreasing. What are we calling this point in calculus terms