Practice problem
Integrating to Find Net or Accumulated Change

Image by RonPorter via https://pixabay.com/en/restaurant-cafe-einstein-restaurant-563127/
Hayley is starting work as a waitress at a restaurant in her hometown. She knows that the restaurant opens at AM (time hours) and closes at PM (time hours) every day.
The number of occupied tables in the restaurant is modeled as a function of time: .
In selecting a shift, Hayley's strategy is simple: pick a block of time with a lot of customers to maximize the amount of money she earns in tips.
If her manager asks her to select a single, continuous -hour shift between AM and PM, what shift should she select to maximize the amount of tables that are occupied while she works?