HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 27

Getting started

1-15

Trig Explorer aplet

The

Trig Explorer

aplet is used to investigate the

behaviour of the graph of

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

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

.

The arrow keys change the

amplitude and frequency of

the graph. This is most easily

seen by experimenting.

Pressing

displays the

equation at the top of the

screen. The equation is

controlled by the graph.

Pressing the

and

keys moves from parameter

to parameter. Pressing the

or

key changes the

parameter’s values.

The default angle setting for this aplet is radians. The

angle setting can be changed to degrees by pressing

.

y

a

bx

c

+

(

)

d

+

sin

=

Origin

π

21

,

⁄

(

)

Extremum

hp40g+.book

Page 15

Friday, December 9, 2005

1:03 AM

HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 27

Trig Explorer

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