HP 39g Graphing Calculator - Manual (Page 26)

Trig Explorer The Trig Explorer aplet is used to investigate the behaviour
aplet of the graph of >> = as,m(bx + c) + d as the values of a, h, 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.
When the user presses
in the [ilitiJ view, the screen
shown right is displayed. V= SinCK)
.‘•'“X .X 3 /'
I
y= SinCH-.g33lT) - ?
r- Origin
In this mode, the graph
controls the equation. Pressing
the 0 0 and Q [►] keys
transforms the graph, with
these transformations reflected
in the equation.
The button labelled IMIEID is a
toggle between M
When is
chosen, the ‘point of control’ is
at the origin (0,0) and the
fT] frl and 0 0 keys
control vertical and horizontal
transformations. When aai.il3 lBGE3l$EB0aBa^^lEHaHll
is chosen the ‘point of control’ is on the first extremum of the
graph (i.e. for the sine graph at (n/2,1).
The arrow keys change the
amplitude and frequency of the
graph. This is most easily seen
by experimenting.
Pressing |SYMB| displays the
equation at the top of the
screen. The equation is
controls the graph. Pressing the
Q and Q keys moves from
parameter to parameter.
Pressing the or Q 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 I ¡TIM.
1-14 Getting started