A certain countrys gross domestic product gdp in millions

Question

Question: A certain country's gross domestic product (GDP) (in millions of dollars) is described by the function

G(t) = -2t³ + 45t² + 20t + 6000       (0 ≤ t ≤ 11)

where t 0 corresponds to the beginning of 2000.

a. At what rate was the GDP changing at the beginning of 2005? At the beginning of 2007 ? At the beginning of 2010 ?

b. What was the average rate of growth of the GDP over the period 2005-2010?