1) The company's sales are seasonal with peak in mid-December and lowest point in mid-June. Company makes $100,000 in sales in December, and only $20,000 in June.
i) Determine a trigonometric function, s = f(t), indicating sales at time t months after mid-January.
ii) What would you expect sales to be for mid-April?
iii) Determine t-values for which s = 60, 000. Interpret the answer.