The domain is the set of values of the independent variable, x, for which the function f (x) is defined; the set of values of the dependent variable is called the range. For example, let the function by y = x ², with x restricted to 0, 1, 2, 3, –3, and –5. Then y takes the values 0, 1, 4, 9, and 25 respectively. The domain is [0, 1, 2, 3, –3, –5] and the range is [0, 1, 4, 9, 25].