HP 39gs Master Manual page 22

The VARS key
Shown right are two views of the
list showing the graphic variables (memories)
from the list showing some of the variables in the set controlling
APLET
.
PLOT
The key is not generally used much, and you may not have
VARS
followed this explanation. This is not important as it is a key that is very
rarely used by the average user. A few uses for the average user are
detailed in the Function aplet's "Expert User" section on page 62.
The key next to
MATH
huge library of mathematical functions. The more common functions have keys
of their own, but there is a limit to the number of keys that one can put on a
calculator before it takes too long to find the key required. Hence the
The menu lists all those functions that would not fit onto the
MATH
keyboard plus some which also appear on the keyboard. Shown in the
screen snapshot right is a small selection of the total list. For a listing of
almost all the functions, with examples of their use, see the chapter
entitled "The MATH Menus" on page 165.
As is usual with all calculators, most of the keys have another function above
the key. The hp 39gs and hp 40gs get twice the action from each key by
having this second function.
The second function is accessed via the
sometimes tell you explicitly to press this key, in most cases it will be assumed that you are intelligent enough
to work out for yourself when it is necessary to press it.
The key is used, mainly by programmers, as a compact way to access all the
VARS
different variables stored by the calculator including aplet environment variables.
screen, the first from the
VARS
G1
is far more important and provides access to a
VARS
SHIFT
HOME
, .... and the next
G2
MATH
key on the left side of the calculator. Although this book will
22
key.