Calcuator forensics history question

[lmamakos]

(04-19-2021 06:08 AM)JimP Wrote:  Most of us are familiar with Mike Sebastian's standard 9 sin cos tan arctan arccos arcsin routine to compare the precision of assorted calculator makes. But it wasn't the first forensics sequence that I encountered -- many years ago (>40 at least!) I seem to recollect the following being used, but I can't recall which make or model's manual suggested it. The sequence is as follows (at least in RPN, degrees mode):

29 sin cos tan ln 1/x 1/x e^x arctan arccos arcsin.

It adds a few more operations, in other words.

I was wondering if anyone else remembers this and if so, where it might have come from?

(For the record, my WP34S returns a value of 29 in double precision mode, and my HP Prime gives 29.0000023889 -- exactly the same as my HP 27S -- and my TI 36X Pro yields 29.00000017.)

I tried this on my HP 50gs running newRPL firmware. Just for fun, I set the precision to 1000 digits.

The result is displayed as 29.0. with the trailing '.' indicating not exact). When I subtract 29, the residual is -5.8044.E-994 which seems well within the ballpark.

My HP 48G gives me 29.0000023889. This apparently is a standard HP result.