Annual sales of bottled water in the country in the period 1993-2003 could be approximated by the function below, where t is time in years since 1990. Were sales of bottled water accelerating or decelerating in 2000? How fast?

Question

R(t) = 10 t**2 + 100 t + 2400 text( million gallons ) \(3<=t<=13\)
Correct: Your answer is correct. by Incorrect: Your answer is incorrect. million gals/

Answer 1

Since R increases with t for any t>0 the answer to the first question requires no computation

R = 10 t^2 + 100 t + 2400 million/year
dR/dt = 20 t + 100
in 2000 t = 10
dR/dt = 20(10) + 100 = 300 million/year^2