A button is provided to evaluate the student’s knowledge. Pressing 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

button is provided for those who give up!

Trig Explorer aplet The Trig Explorer aplet is used to investigate the behaviour of the graph of y = a sin (bx + c) + d as the values of a, b, c and d change, both by manipulating the equation and seeing the change in the graph, or by manipulating the graph and seeing the change in the equation.

Press , select Trig Explorer, and then press to display the screen shown right.

In this mode, the graph

 

 

 

 

 

 

 

 

 

 

 

 

 

 

controls the equation.

 

 

 

 

 

 

 

Pressing the

 

 

 

 

 

 

and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

keys

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

transforms the

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

graph, with these

 

 

 

 

 

 

 

 

 

 

 

 

 

transformations reflected in the equation.

 

 

 

The button labelled

 

 

 

 

 

 

is

 

 

Origin

 

 

 

 

 

 

 

 

 

 

 

 

 

 

a toggle between

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and

 

 

 

 

. When

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

is chosen, the ‘point of

 

 

 

 

 

 

 

control’ is at the origin (0,0)

 

 

 

 

 

 

 

and the

 

 

 

 

 

and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

keys control vertical and

 

 

 

 

 

 

 

 

 

 

 

 

 

 

horizontal transformations. When

 

is chosen the

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

‘point of control’ is on the first extremum of the graph (i.e. for the sine graph at (π ⁄ 2,1) .

The arrow keys change the

Extremum

 

 

 

amplitude and frequency of

 

 

 

 

 

 

 

the graph. This is most easily

 

 

 

 

seen by experimenting.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Getting started

1-15

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Image 25
HP 39g+ Graphing manual Keys Transforms Graph, with these, Amplitude and frequency, Seen by experimenting