19. A companys marginal cost function is where x is the number of units. Find the total cost of producing units 144 to 625. Find the cost function, take the anti-derivative of the marginal cost function. If f(x) = k xn , where n is a rational number other than 1 and k is a constant, then F(x) = k xn + 1 (n + 1) + C. To find the cost of producing units 144 through 625, evaluate the anti-derivative on the interval [144, 625].

20. A technician can test video player chips at the rate of chips per hour (for ), where t is the number of hours after 9:00 am. How many chips can be tested between 11:00 a.m. to 3:00 p.m.? (Assume for 9:00 a.m.) find the total number of chips processed after t hours. If f(x) =k xn, where n is a rational number other than 1 and k is a constant, then F(x) = k xn + 1 (n + 1) + C. To find the total number of chips tested from 11:00am to 3:00pm (assuming t = 0 at 9:00am), evaluate the anti-derivative on the interval [2, 6].