Enter the Y Editor on your calculator. Most graphing calculators will have a “Y=” button that you can press to enter the editor.
Enter the expression using the alphanumeric keypad, without typing the “Y=.” For example, y= 2x + 2 would be entered on the calculator as 2x + 2. (The ^ symbol normally has its own key.)
Graph the equation. Most graphing calculators have a “Graph” button.
Press the “Trace” button on your calculator. This slides along the length of the graph, giving you every possible output for the function. To find an output for a specific value of X, just enter the number into the calculator. For example, if you want to know what the Y value is for an input of 2, enter “2” into your calculator after pressing the “Trace” button.