The shipments of Lica digital singlelens reflex cameras (SLRs) are projected to be N(t) = 6t2 + 200t + 4 √t + 20,000 (0 ≤ t ≤ 4) units t years from now. How many Lica SLRs will be shipped after 2 years? At what rate will the number of Lica SLRs shipped be changing after 2 years?