HP 39gs Master Manual page 29

Suppose we define a trig function in the
Function aplet as shown.
The default setting for the Function aplet is
radians, so if we set the axes to
π π
extend from - to , the graph would
look as shown right.
In the view shown, the first positive root has been
PLOT
found (see page 57) as x=1.0471...
On the hp 39gs and hp 40g, if we now change to the
retrieve the root and perform the calcul
the answer should be zero, as indeed it is.
However, this is only the case because the angle measures of
problem was that on the original hp 38g the default setting for the Function aplet was radians, while
had a default setting of degrees and its setting was independent of those of the aplet. This meant that a
calculation such as the one above would give incorrect results, and caused considerable confusion to some
students. It even resulted in users returning their hp 38g to dealers as being 'faulty'! Hence the change, which
was first made in the hp 39g and hp 40g.
The only drawback of synchronizing the settings of the
is that you might change aplets and forget that it may also change the
view settings. For this reason, the name of the active aplet is
HOME
shown at the top of the
On the hp 39gs and hp 40gs
you can see that if we turn
on and then
Labels PLOT
the numeric mode also affects
the axis labels.
The default behavior in the
to the way that they often interfere with the clear display of the graph.
ation shown right, we expect that
view as a reminder.
HOME
,
view is to not display axis labels due
PLOT
view,
HOME
and the Function aplet agree. The
HOME
and aplet
HOME
29
HOME