60 1. Sample Examination II Section II Part A: Graphing Calculator MAY BE USED. The temperature T(x), in F, in a small office building without air conditioning is given by T(x) = 73-14 cos((234)) where r is the time elapsed since midnight, 0x 24. 12 To cool the building, the air conditioning is turned on when the temperature first reaches the = 18). desired temperature To and left on until the office closes at 6:00pm (that is, when x = -18 The cost per day, in dollars, of cooling is given by C(x) 16 [ (T(z) To) dx for 0.16 T(x) > To. = (a) Estimated to the nearest half-hour, at what time will the temperature first reach 70F? (b) Estimated to the nearest half-hour, at what time will the temperature first reach 77F? (c) What is the cost per day of cooling the office if the desired temperature is 70F? Show your reasoning. (d) How much is saved per day if the desired temperature is raised to 77F? (a) Estimated to the nearest half-hour, at what time will the temperature first reach 70F