A company’s sales are seasonal with the peak in mid-December and the lowest point in mid-June. The company makes $100,000 in sales in December and only $20,000 in June.
(a) Find a trigonometric function, s = f(t), representing sales at time t months after mid-January.
(b) What would you expect the sales to be for mid-April?
(c) Find the t-values for which s = 60,000