Based on data from 1999 to 2001, the rate of change in the annual net sales of Pepsi-Cola North America may be modeled by
R(t) = −131t − 749.5 million dollars per year
and the rate of change in the annual operating profit may be modeled by
P(t) = 12t + 76 million dollars per year, where t is the number of years since the end of 1999.
Determine the accumulated change in annual operating costs from the end of 1999 through 2001 by finding the area between these two curves. Graph the two equations on the same set of coordinate axes.