How to Find Domain and Range From a Graph

Read the domain along the x-axis and the range along the y-axis. Check whether boundaries belong to the function.

Square-root example

Enter sqrt(x-2). The graph starts at (2,0), so the domain is [2,∞) and the range is [0,∞).

Reciprocal example

For 1/(x-2), x=2 is excluded from the domain and y=0 is excluded from the range. Expand the window to inspect each branch.

Try the Graphing Calculator.