Final answer:
The inverse of f does not exist.
Step-by-step explanation:
Given the function f(x) on the domain {1,5}, we need to determine if the inverse of f exists or not. To find the inverse, we need to check if each value in the range of f corresponds to a unique value in the domain. If there are any repeated values in the range, the inverse does not exist. In this case, since the domain is restricted to {1,5}, and the function is defined by a horizontal line, f(1) and f(5) both have the same value. Therefore, the inverse of f does not exist.