Quadratic Function (General Form & Discriminant)
How to Use this Applet
The Slider Area
The sliders change the parameters a, b and c in the quadratic function y = ax² + bx + c.
 Drag a slider to change the value of a parameter.
 The <LEFT> and <RIGHT> arrow keys can be used to change the selected parameter [light blue].
 The <UP> and <DOWN> arrow keys can be used to increase or decrease the selected parameter. (Use this feature for fine adjustments.)
 If the arrow keys don't respond, click the cursor in he applet frame then try again.
 Drag a parameter scale to "move" it. (I.e., change the range but maintain the scale "length".)
 Drag towards or away from a parameter thumb to "rescale" the scale.
 Select the corresponding parameter button to enter a value for a parameter.
The Graph Area
 Drag the vertex to move the parabola in the coordinate system.
 Drag a location along the axis of symmetry of the parabola (other than the vertex) to move the parabola only horizontally or vertically.
 Drag a location along the parabola (other than the vertex) to change the width of the parabola.
 The <SHIFT> key: Click and drag in the graph area to move the entire coordinate system.
 The <CONTROL> key: Click and drag in the graph area towards or away from the origin to change the x and y axis scale.
 The <CONTROL>+<SHIFT> key: Click and drag in the graph area towards or away from the:
 xaxis to change the yaxis scale.
 yaxis to change the xaxis scale.
Other
 Use the "RESET" button to restore the applet to the initial state.
