申論題

3. Based on a recent study, the “happiness” of people who live in a country whose average temperature is t degrees Fahrenheit is given by h(t ) = 8.2 − (0.01t − 2.8) ² , for 35 ≤ t ≤ 72 (“Happiness” was rated from 1 = “not at all happy” to 4 “very happy”.) Find h (40) and h ' (40) . Interpret your answer.