You and your friend are hiking down a mountain after a rigorous
ascent to the top. After 1 hour, your elevation is 6,650 feet. After 2
hours, your elevation is 5,985 feet. After 3 hours, your elevation is
5,320 feet. This pattern continues. Let n represent the number of
hours you I have been hiking.
Write a function f(n) to represent the elevation after n hours.