Final answer:
The domain of a function is the set of all possible x-values, and the range is the set of all possible y-values. A horizontal line has a constant y-value, but the y-value isn't provided. Therefore, we cannot determine the range without more information.
Step-by-step explanation:
Understanding the domain and range of a function is essential in mathematics. The domain is the set of all possible input values (x-values) for which the function is defined, while the range is the set of all possible output values (y-values) that the function can produce.
Given the description of the graph of a function f(x) being a horizontal line that exists between x = 0 and x = 20, inclusive, we can determine the domain and range. Since the line is horizontal, this means that the y-value remains constant for all x-values within the domain. Thus, we need to identify the constant y-value. However, since this information isn’t provided in the question, we're unable to answer without making assumptions.