Re: HP35s Cos[x] and Tan[x] bugs resolved? Message #2 Posted by Dieter on 31 Oct 2013, 9:27 a.m., in response to message #1 by Thomas Windisch
First of all, cos 90° should return zero, and so does the 35s. On the other hand, cos 89° gives 0,0174524064373, the value you posted. And cos 89,99999° returns 1,7453292 E7 both on your machine as well as on my early 35s bought in 2007.
So I do not think that anything has changed  the results of my early and your current 35s agree. The "bug" you mentioned refers to the loss of accuracy with arguments close to 90 degrees. In this case, the second result carries merely eight significant digits (out of twelve) with the last one truncated, not rounded:
cos 89,9999 1,74532925 E6
cos 89,99999 1,7453292 E7
cos 89,999999 1,745329 E8
cos 89,9999999 1,74532 E9
cos 89,99999999 1,74532925199 E10 ...back again ;)
Dieter
