To all who might be interested, here is another trigonometric program specially for the HP 35s.

HP 35s trigonometric functions (sin, cos and tan) alternative

Quote:

The HP 35s's built-in trigonometric functions seems to lose its accuracy around }ƒÎ/2, }ƒÎ/4, }ƒÎ3/2 and so on. In some case its accuracy goes down to seven digits or less which is not acceptable as the scientific calculator that features internal 15 digits precision. Anyway as it was necessary, I wrote the alternative trigonometric functions for the HP 35s. [Aug. 30, 2007]

Best regards,

Lyuka