The US Geological Survey Estimates That the Normal Stream Flow of of the Potomac

Short Answer

The U.S. Geological Survey estimates that the normal stream flow of the Potomac River (in millions of gallons per day) is given by the function $f ( t ) = 4200 + 3000 \cos \left( \frac { \pi } { 6 } t + \frac { 5 \pi } { 12 } \right)$ where t denotes the number of months after January 1. Determine the maximum and minimum daily stream flows of the Potomac River. Enter your answer exactly as a, b where a represents the maximum and b represents the minimum,both integers separated by a comma, no units or words.