Final answer:
The city of Cusco in the Inkan Empire served as the capital, represented the four divisions of the empire, divided the city into upper and lower classes, and controlled the inhabitants.
Step-by-step explanation:
The function of the city of Cusco in the Inkan Empire was all of the above. Cusco served as the capital of the Inkan Empire, representing its four divisions and controlling its inhabitants. It also played a role in dividing the city into upper and lower classes, with the ruling elite residing in the city.