HP35s Revisited Trig Quandary Bug # 2

[MarkHaysHarris777]

(02-17-2015 02:36 AM)Jeff_Kearns Wrote:  My 1973 HP-35 gives: 1.7451419E-06

Thanks for the candor, Jeff... and for the data.

So, the 1973 HP35 (in fact the one that has the 2.02 bug fixed, I think) is showing significant figures that are not correct (which you should expect since the HP35 did not double the internal digits for intermediate results on its series expansion; QED, the digits after 1.745 are wrong.

Back in the day folks were not aware of this, mostly... and most people back in the day did not have a good way to cross check, like we do today. Mathematicians of course would know that working trig convergences near pi/2 or -pi/2 would be a problem... in fact, I think there was a warning about it in the literature that came with the HP35 in the beginning (someone with a book could check for me... please)

At any rate, the revised HP35s 'improved' upon its predecessor in a BIG way... and since the HP35s was supposed to be a celebration of the HP35 original, that is what is important... in other words, I do not look upon the HP35s as a step backwards (compared to the 42s, 15C), rather, as a step-up from the original HP35!

PS I'm wondering if the engineers at HP (Kinpo) compared the HP35s against the HP42s, or HP15C? I'll bet not. I know that seems unbelievable, but I'll bet (if I was a betting man, and I'm not) that I'm right... be interesting to find out (anybody want to speak up?)

Cheers,
marcus