Chapter 8.2, Problem 68E

Seasonal business cycle. Revenues from sales of a soft drink over a 2-year period are given approximately by

     $R\left(t\right)=4-3\cos \frac{\pi t}{6}0\le t\le 24$

where R(t) is revenue (in millions of dollars) for a month of sales t months after February 1. The graph of the revenue function is shown in the figure.

(A)    Find the exact values of R(0), R(2), R(3), and R(18) without using a calculator.

(B)    Use a calculator to find R(5) and R(23). Interpret the results.

(C)    Use a graphing calculator to confirm the graph shown here for y = R(t).