Quad Explorer aplet

H I N T

The Quad Explorer aplet is used to investigate the behaviour of y = (x + h)2 + v as the values of a, h and v change, both by manipulating the equation and seeing the change in the graph, and by manipulating the graph and seeing the change in the equation.

More detailed documentation, and an accompanying student work sheet can be found at HP’s web site.

When first started, the aplet is in *53+a￿amode, in which the arrow keys, the >￿@ and >￿@ keys and the >￿ @ key are used to change the shape of the graph. This changing shape is

reflected in the equation displayed at the top right corner of the screen, while the original graph is retained for comparison. In this mode the graph controls the equation.

It is also possible to have the equation control the graph. Pressing 6<0%￿adisplays a sub-expression of your equation (see right).

Pressing the *A,￿and *>,￿key moves between sub- expressions, while pressing the *k,￿and￿*e, key changes their values.

Pressing /(9(/aallows the user to select whether all three sub- expressions will be explored at once or only one at a time.

A 7(67abutton is provided to evaluate the student’s knowledge. Pressing 7(67a displays a target quadratic graph. The student must

manipulate the equation’s parameters to make the equation match the target graph. When a student feels that they have correctly chosen the parameters a &+(&.button evaluates the answer and provide feedback. An $16:abutton is provided for those who give up!

Getting started

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HP 40G manual Quad Explorer aplet, N T