(a) According to the 20th report of the International Commission on Whaling, the number N of fin whales in the Antarctic for the period 1958-1963 was estimated to be where t = 0 corresponds to January 1958, t = 1 corresponds to January 1959, and so on. According to this equation, how many fin whales would be left in April 1960?
(b) If the decrease continued at the same rate, when would there be no fin whales left? (Actually, the 1993 estimate was approximately 21 000)