A franchise models the profit from its store as a continuous income stream with a monthly rate

Question:

A franchise models the profit from its store as a continuous income stream with a monthly rate of
flow at time t given by f (t)=3000e0.004t (dollars per month) When a new store opens, its manager is judged against the model, with special emphasis on the second half of the first year. Find the total profit for the second 6-month period (t=6 to t=12).