The domain of a function is the set of all possible x-values. The range is the set of all possible y-values. Notice that, horizontally, our graph spans from x=0 to x=6, inclusive. These values are the lower and upper boundaries of our domain. D: 0≤x≤6 Meanwhile, vertically, our graph spans from y=-1 to y=2, inclusive. These values are the lower and upper boundaries of our range. R: -1≤y≤2