This applet is designed to allow a visual exploration of a family of function, or how shifting a parameter changes the graph.
The applet opens with the function f(x) = a*x^2 + b*x + c.
The sliders on the side let you change the parameters.
To change the function, right-click (control-click for mac
people) on the formula and choose "redefine" from the context menu that
pops up. To change the viewing area, right-click on bank
space in the graphing pad and choose "properties".