I want to know how to take the deravative of this function

Question

The per capita consumption of breakfast cereal in the US has the following model that appears above

C(t)=-0.0035t^3+0.112t^2-0.351t+13 pounds, where t is the number of years since 1990.

Decide whether the rate of consumption was changing more rapidly in 2002 or 2009.

C′(12) =    lbs/year

C′(19) =    lbs/year

Answer 1

Use the Power Rule.