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where is 35s cos bug - Printable Version

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where is 35s cos bug - Andrew Nikitin - 10-05-2008

It was mentioned that 35s cannot proprely calculate cos (and some other trig functions) in certain ranges.

Where can I find examples with an appropriate argument and erroneous result given by 35s? I cannot seem to find the bad inputs.

Re: where is 35s cos bug - George Bailey (Bedford Falls) - 10-05-2008

Do a Google site search like so:

cos bug hp 35s

Re: where is 35s cos bug - Andrew Nikitin - 10-05-2008

Google finds numerous pages with a sentence "Cos(x) for x near 90 is dud". It also, surprisingly, finds this very thread.

However, what I am trying to find is actual numeric example of X where cos X is calculated incorrectly by 35s.

If found mentions of "cos(89.999) bug", but my 35s says
cos(89.999)=1.74532924306e-4 which agrees to 9 digits with what PC tells me. Is that a bug? That it is only 9 digits? Must be all 12?

Edited: 5 Oct 2008, 10:39 p.m.

The HP-33s/35s trig bug, tabulated - Karl Schneider - 10-06-2008

Andrew --

Here is what you seek:


The new HP-20b gives all correct results, so I believe that the bug has been addressed, and will not recur.

-- KS