Press "Add Function" button and type in a formula to be graphed in
standard mathematical notation (eg "e^(-x/10)sin(x)"). The only
variable the formula can use is x. Use Pi for pi; for
example, sin(Pi/2 x). You can add as many functions as you
like, and "Delete Function" deletes the last one you entered.
Rescaling
This brings up a panel which you can use to edit the scale of the
graph. The x variable runs between xMin and
xMax, and the y values run between yMin and
yMax. Use xScale and yScale to set the
spacing of tick marks on the axes. If xScale or yScale
is zero, the graph will have no tickmarks on that axis.
Zooming
You can change the scale of your picture quickly with "Zoom In",
"Zoom Out" and "Zoom to Box". The first two zoom in or out around the
center of the graph. If you click and drag on the graphing window, you
can draw out a box, and Zoom To Box will zoom in to make that
box fill the whole window.