Re: Trig Error
- To: mathgroup@smc.vnet.net
- Subject: [mg11430] Re: [mg11396] Trig Error
- From: Mark Evans <evans@gte.net>
- Date: Thu, 12 Mar 1998 01:33:08 -0500
- Organization: None
- References: <199803090113.UAA06476@smc.vnet.net.>
LHDill wrote: > > I discovered an error in the trigonometry functions of all places. > > The exact value of Cot [11/2 Pi] is zero, but Mathematica 3.0 gives > ComplexInfinity (!) for the nearly equivalent > Cot[17.2787595947438628115445386080397220812326`30.2181]. > > Has anyone else noticed similar trig errors? > > Loren Dill Yes -- something similar happened to me 3-4 years ago. It was something to do with Cot[] if I remember, not behaving the same for exact input as identical numerical input, and not using Degree properly. Seems like a long time to retain the same old bugs.... Mark > This is a bug confirmed by Wolfram Research tech support. --- > > FullSimplify@(Integrate[Simplify[D[#,x]],x]-#&)@(Cosh[Cosh[x]^3+Sinh[x]^8]) > > I expect it to return a constant, but FullSimplify took 50 megabytes of > kernal memory and still running. (~20 minutes) I don't have the > resources to complete it. I'd be interested to know what it returns if > anyone finds out. > > This is on a MacOS8.0, Mathematica 3.0.1.1x. The bug is fixed in the > coming version, tech support said. > > Xah, xah@best.com > http://www.best.com/~xah/PageTwo_dir/more.html
- References:
- Trig Error
- From: lhdill@aol.com (LHDill)
- Trig Error