Find and enter the "plot function" screen. This screen is a list of equations, starting with “y =” that allows you to finish the equation. You can find this screen through the menu list on your calculator. Many graphing calculators make this screen easily accessible by having a button labeled “y =” near the top of the calculator.

Enter the function you wish to graph. Because the “y =” part of the equation is already taken care of by the calculator, you need only enter the remaining part of the equation. This remaining part usually includes a variable. Graphing calculators require you to use “x” as the variable, because the default axes of graphing are the x-axis and y-axis. Enter your equation with the number buttons as well as the “x variable” button. For example, if you wish to graph the equation “y = x – 3,” press “x variable,” "-" and “3.”

Find the graphing window screen. This screen allows you to determine the length of the x and y-axes. Many graphing calculators allow access through this screen with a button labeled “window.”

Set up the size of the graphing window. Many functions can only be seen through the creation of an appropriate window size. For example, the graph “y = 100” cannot be seen if the window size does not allow the y-axis to extend beyond 100. When you know where the axes should begin and end for the graph, enter the values into the four spaces labeled “y-min,” “y-max,” “x-min” and “x-max.” For example, when graphing “y = x - 3” you should assure that the y-axis goes beyond -3 so that you can see the y-intercept. Enter a value below -3 for “y-min” and whatever you like for the other three spaces.

Call the graph function. Press the “graph” button to display the graph.