Trigonometric Functions for the HP-38C/HP-12C

[Gerson W. Barbosa]

Bob,

Please take a look at the new version in the other sub-forum. I used four steps I've managed to free to implement error handling for asin(1). I should've added another constant for the sine polynomial instead. This requires only two steps and one register. The sine polynomial is less accurate than the arctangent polynomial. This shouldn't be difficult to do as the four new constants could be the same listed in the hp 12c Platinum article. I'm not sure if the results for cosine and tangent for arguments near 90 degrees will be significantly improved as I've used other formulas in the 12c platinum program.

Regards,

Gerson.

P. S.: Done that (added extra constant to the sine polynomial using the aforementioned constants).

Now I get

tan(89.0000) = 57.289961(72)

tan(89.9900) = 5729.57(8904)

tan(89.9999) = 57205(2.5534)

Asin(1) = 90 degrees is gone, now Error 0 shows up instead. But who needs it anyway?

Sunday is almost over. Tomorrow I will recompute the constants, but no much more improvement should be expected.