The revenue generated from sales of a tablet changes at a rate given by

l r 1 r The revenue generated from sales of a tablet changes at a rate given by R (t) = (2t + 4)(l'2 + 4t)( /3), where R (t) is measured in hundreds of thousands of dollars per year and t is measured in years since 2000. The cost to produce the same tablet changes according to C (t) = 290'\