hp 39g+ (39g & 40g)_mastering the hp 39g+_English_E_F2224-90010

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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.
Objectives
Using the Trig Explorer aplet, the student will investigate the behaviour of the
graph of sin( )ya bxc 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.
When the student presses , 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.
SIN vs. COS
The (or ) key can be used to
toggle between the
()
sin
y
x= curve and the
()
cosyx=
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).
SYMB vs. GRPH mode
The Trig Explorer aplet can be used in two
modes:
SYMB mode - the equation controls the graph (press the SYMB key).
and PLOT 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.