Quadratic Function
(Vertex Form)

How to Use this Applet

The sliders change the parameters a, p and q in the quadratic function y = a( x − p )² + q.

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 "re-scale" the scale.
Select the corresponding parameter button to enter a value for a parameter.

Drag the vertex to move the parabola in the coordinate system.
Drag a location along the parabola (other than the vertex) to change the width of the parabola.
Click and drag any location in the graph area (not on the parabola) to see the coordinates of the cursor as well as the coordinates of locations along the graph.
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:
- x-axis to change the y-axis scale.
- y-axis to change the x-axis scale.