Final answer:
The reasonable domain of the function is likely the set of whole numbers greater than or equal to zero, which takes into account practical constraints that are not reflected in the mathematical domain.
Step-by-step explanation:
The reasonable domain of a function differs from the mathematical domain in that it takes into account real-world constraints on the variables, which may limit the set of possible inputs. For the function f(x) = 16.4x + 2, which estimates the amount of fuel required for a truck to reach a job site based on the miles x from the office, the mathematical domain is all real numbers, reflecting all possible distances. However, the reasonable domain is likely restricted to non-negative values since negative distance does not make sense in this context. Moreover, since we're dealing with a practical scenario involving distances, we would typically only consider whole numbers or integers, as fractional or irrational distances would not be practical for measuring. Therefore, the reasonable domain for this function is most likely the set of whole numbers greater than or equal to zero.