The graph of f(x) = 5, when restricted to 0 ≤ x ≤ 20, is a horizontal line starting at (0,5) and ending at (20,5), only existing within that domain.
If you suppose f(x) = 5, this describes a graph of a horizontal line where the y-value is consistently 5 across all x-values from 0 to 20.
When graphing f(x), the line will run parallel to the x-axis and will pass through the point (0, 5) on the y-axis. It will continue straight until x = 20, making it a restricted function.
This limited domain means f(x) exists only between x = 0 and x = 20, inclusive.
Moreover, if you compare the graph of f(x) to the graph of a constant function without restrictions, the only difference is that the unrestricted graph of a constant function like f(x) = 5 would extend indefinitely in both directions along the x-axis.