please help me answer this

14. [-/2 Points] DETAILS LARCAAPCALC2 11.3.056. MY NOTES The rate of change in revenue for Under Armour from 2004 through 2009 can be modeled by dR = 13.897t + 284.653 dt where R is the revenue (In millions of dollars) and t is the time (in years), with t = 4 corresponding to 2004. In 2008, the revenue for Under Armour was $725.2 million.+ (a) Find a model for the revenue of Under Armour. (Round your constant term to two decimal places.) R(t) = (b) Find Under Armour's revenue in 2004. (Round your answer to two decimal places.) $ million