Chapter 8.3, Problem 48E

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

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

where R(t) is revenue (in millions of dollars) for a month of sales t months after February 1.

(A)    What is the rate of change of revenue t months after February 1?

(B)    What is the rate of change of revenue 1 month after February 1? 6 months after February 1? 11 months after February 1?

(C)    Find all local maxima and minima for 0 < t < 24.

(D)    Find the absolute maximum and minimum for 0 $\le$ t $\le$ 24.

(E)    Repeat part (C), using a graphing calculator.