[color=#0][br]Before using this applet you should know about the "completed square" or "vertex" form of a quadratic equation.[br][/color]

[color=#0]Use the sliders to change the values of the parameters in the completed squrae form of the equation.[br]See how the shape of the graph varies.[br]Fit a quadratic graph to the points (1, 5) (the vertex), (2, 6) and (3, 9)[br]Fit a quadratic graph to the points (-3, -2) (the vertex), (-2, 0) and (-1, 6)[br]Try to work out what the equation will be first, and then use the applet to check your solution.[br][/color]