g(Math) offers the ability to customize the viewing window of your graph. I personally feel like this is the most powerful aspect of g(Math)! By default the viewing window is set from -10 to 10 on both the x and y axis. Enter the values you would like to see in the viewing window to change it.
These boxes are "smart" and you can even enter the values in terms of Pi, great for Trig functions!
I am currently working on the ability to change the step size on the axes. You can also populate these values from a graph already in your Doc (or Sheet). Click on the graph in the Doc and then Click the Edit from Doc button. The axes values will populate from the graph that was selected.