HP 50g Graphing Calculator - Manual (Page 185)

Page 5-8
LNCOLLECT, and TEXPAND are also contained in the ALG menu presented
earlier. Functions LNP1 and EXPM were introduced in menu HYPERBOLIC,
under the MTH menu (See Chapter 2). The only remaining function is EXPLN.
Its description is shown in the left-hand side, the example from the help facility is
shown to the right:
Expansion and factoring using trigonometric functions
The TRIG menu, triggered by using ‚Ñ, shows the following functions:
These functions allow to simplify expressions by replacing some category of
trigonometric functions for another one. For example, the function ACOS2S
allows to replace the function arccosine (acos(x)) with its expression in terms of
arcsine (asin(x)).
Description of these commands and examples of their applications are
available in the calculator’s help facility (IL
@HELP). The user is invited to
explore this facility to find information on the commands in the TRIG menu.
Notice that the first command in the TRIG menu is the HYPERBOLIC menu,
whose functions were introduced in Chapter 2.