The gates of an amusement park are closely monitored to determine whether the number of
people in the amusement park ever poses a safety hazard.
On a certain day, the rate at which people enter amusement park is modeled by the function
e(x) = 0.03x^3 + 2, where the rate is measured in hundreds of people per hour since the gates
opened. The rate at which people leave the amusement park is modeled by the function
l=(x)=.5x+1 where the rate is measured in hundreds of people per hour since the gates
opened
What does (e - 1)(4) mean in this situation?