Range of a function is which of the following?

• A. All the X values in a function
• B. The slope of the function
• C. The vertex coordinates
• D. All the Y values in a function

Answer: (D)

The range is the set of all y-values a function can produce as x runs through its domain. It tells you how high or low the graph goes vertically. This isn’t about the x-values (that’s the domain), nor about the slope (rate of change), nor about a vertex (a single point that might describe a graph’s shape). So the best description is the set of all possible y-values—the outputs of the function. For example, y = x^2 with all real x has range y ≥ 0, showing the vertical extent of the graph.