Ellipse and Hyperbola (Quadratic Relations)
How to Use this Applet
The Slider Area
The sliders change parameters h, k, a and b in the quadratic relation.
 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 the 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 center of the graph to move it in the coordinate system.
 Drag a vertex or covertex of the graph to change parameters a or b.
 Drag a vertex or covertex of the rectangle to change parameters a and b.
 Click and drag any other location to see the coordinates of the cursor and locations along the graph of the relation.
 Move the cursor into the equation area to see which type of relation (horizontal or vertical) is being displayed.
 The <SHIFT> key: Click and drag in the graph area to move the entire coordinate system.
 The <CTRL> key: Click and drag in the graph area towards or away from the origin to change the x and y axis scale.
Other
 Use the "RESET" button to restore the applet to the initial state.
