Final answer:
The question involves determining which function represents a horizontal line for the interval 0 ≤ x ≤ 20. The correct function is f(x)=20/20, which simplifies to f(x)=1, a constant function representing a horizontal line at y=1 within the given domain.
Step-by-step explanation:
The student has asked about determining which function could correspond to a given graph. To address this, it's necessary to analyze each provided function and match it with the characteristics of the graph described. The mention of the function being constant on a certain interval suggests that we are dealing with a horizontal line within the given domain of 0 ≤ x ≤ 20. This implies that the value of f(x) does not change as x varies within this interval.
Given the options, f(x)=√x-2, f(x)=Wx-3+1, f(x)=2x+4, and f(x)=x+1+8, the appropriate function must reflect a constant value. Therefore, f(x)=20/20 matches the description as it simplifies to f(x)=1, representing a horizontal line at y=1 for the interval 0 ≤ x ≤ 20.
To confirm, we can graph the function and notice that, indeed, it represents a horizontal line, thereby answering the student's question. No other provided functions would graph as a horizontal line as they all involve either an increasing or a decreasing relationship due to the variable x.