Answer: choice D) [tex]1 \le x \le 6[/tex]
The function is constant when the graph is a flat horizontal line. In this case, that happens for the portion from x = 1 to x = 6. The slope of this line segment is 0 meaning that there is no change in y as x increases (y doesn't go up or go down).
Answer: answer is D
Step-by-step explanation: don’t have much of an explanation but I hope this helps
