HP Forums / HP Museum Forums / Old HP Forum Archives v / where is 35s cos bug

Linear Mode
where is 35s cos bug


▼
Post: #5
10-05-2008, 02:32 PM
Andrew Nikitin Offline
Unregistered
Posts: 117
Threads: 31
Joined: Sep 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.

Find
▼
Post: #6
10-05-2008, 02:35 PM
George Bailey (Bedford Falls) Offline
Unregistered
Posts: 335
Threads: 12
Joined: Dec 2007

Do a Google site search like so:

cos bug hp 35s

Find
▼
Post: #7
10-05-2008, 10:32 PM
Andrew Nikitin Offline
Unregistered
Posts: 117
Threads: 31
Joined: Sep 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.

Find
Post: #8
10-06-2008, 01:41 AM
Karl Schneider Offline
Unregistered
Posts: 1,792
Threads: 62
Joined: Jan 2005

Andrew --

Here is what you seek:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=123880#123880

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

-- KS

Find

Forum Jump: