SIN vs. COS
SYMB vs. GRPH mode
28
T
T
H
H
E
E
T
T
R
R
I
I
G
G
E
E
X
X
P
P
L
L
O
O
R
R
E
E
R
R
T
T
E
E
A
A
C
C
H
H
I
I
N
N
G
G
A
A
P
P
L
L
E
E
T
T
Rather than being a multi-purpose aplet like most of the others covered so far, this is a teaching aplet
specialized to the single use of exploring the graphs of trigonometric functions. As such it does not have the
normal
SYMB
,
NUM
and
PLOT
views, but only a single multi-purpose view. The
SYMB
and
PLOT
keys do
have meanings but not the normal ones.
Objectives
Using the Trig Explorer aplet, the student will investigate the behavior of the graph of
y
a
sin(
bx
+
c
)
+
d
as
=
the values of
a
,
b
,
c
and
d
change. This can be done both by manipulating the equation and seeing the
change in the graph,
or
by manipulating the graph and seeing the change in the equation.
, they will see the main screen of the
aplet, shown right. Like the Quadratic Explorer, this aplet has only one
screen, rather than the usual
PLOT
,
SYMB
and
NUM
views. If the aplet
has been used before then it may be necessary to press the
screen key to go back to the opening view shown.
When the student presses
The
(or
) key can be used to toggle between the
y
=
sin
( )
curve and the
y
=
cos
( )
curve. The
(or
) key
can be used to toggle between radian measure and degree measure.
The markings on the horizontal axis adjust accordingly (see right and
below right).
x
x
The Trig Explorer aplet can be used in two modes:
SYMB
mode - in this mode the equation controls the
graph (press the
SYMB
key).
and
PLOT
mode
- in this mode the graph controls the
equation (press the
PLOT
key).
Which mode is in operation is controlled by pressing the
SYMB
and the
PLOT
keys. The
NUM
key has no
effect in this aplet and the aplet has no
SETUP
views. The ranges for the x and y axes are preset and cannot
be changed.
In both modes the original shape of the sine or cosine graph is left
visible as a dotted line for comparison.
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