1. The problem asks: "Where have we used the range?" in a mathematical context. 2. In mathematics, the "range" of a function is the set of all possible output values (y-values) it can produce. 3. The range is used when analyzing functions to understand the limits of their outputs. 4. For example, when solving inequalities or graphing functions, knowing the range helps determine which y-values are valid. 5. The range is also important in real-world problems where outputs must be within certain bounds. 6. To summarize, the range is used whenever we need to know or restrict the possible outputs of a function or relation.