Resource depletion:-
An oil well starts out producing oil at the rate of 60,000 barrels of oil per year, but the production rate is expected to decrease by 4,000 barrels per year. Thus, if P(t) is the total production (in thousands of barrels) in t years, then
P'(t) = f(t) = 60 - 4t 0<=t<=15
Write a definite integral that will give the total production after 15 years of operation, and evaluate the integral.