Hi,
I have submitted an article to the Articles Forum (Hyperbolic Approximations for Trigonometric Functions on the HP-12C). The 99-step program uses only the stack, leaving the financial registers and all the seven remaining registers free for the user. The average percent error is 0.05% never being greater than 0.10% all through the valid ranges, which is enough for practical purposes. Running times are about 4 to 5.5 seconds, depending on the function only, not on the arguments. All inputs and outputs are in degrees.
For more details, those of you still interested please take a look at:
http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=470
Regards,
Gerson W. Barbosa
Edited: 27 Feb 2005, 8:16 a.m.