A function shows the relationship between two or more variables. A function is said to be constant over an interval if its output value is same for every input value within that interval.
As seen in the question, the x variable is the input while the y variable is the output. The function is constant from x = -4 to x = -2. Also, the function is constant within the interval from x = 4 to x = 7. Hence, the interval is:
