GDP of a Country The gross domestic product (GDP) of a certain country is

f(t) = 0.1t³+0.6t²+2t+23 (0t4)

billion dollars in yeart, wheretis measured in years witht= 0 corresponding to 2010.(a)What was the GDP of the country in2014?

$ billion

(b)How fast was the GDP of the country changing in2014?

$ billion/yr