Save 380 For a company that manufactures tennis rackets, the average cost per racket is found to be C +3+ x for x2 1, where x is the number of rackets produced per hour. Use the differential to approximate the change in average cost per racket if production is (A) increased from 15 per hour to 18 per hour and (B) increased from 40 per hour to 43 per hour (A) If production is increased from 15 per hour to 18 per hour the average cost per racket will decrease by approximately 540 per racket