Re: How do I force Log[Exp[x]]=x
- To: mathgroup at smc.vnet.net
- Subject: [mg22026] Re: [mg21988] How do I force Log[Exp[x]]=x
- From: Laurence Lours <lours at bruyeres.cea.fr>
- Date: Fri, 11 Feb 2000 02:38:09 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
With Mathematica 4, you have just to do Simplify[Log[Exp[x]],x\[Element]Reals] and it returs x. Laurence Lours > From mathgroup-adm at smc.vnet.net Thu Feb 10 08:55 MET 2000 > Date: Thu, 10 Feb 2000 02:25:32 -0500 (EST) > From: sasrbk at unx.sas.com (Bart Killam) To: mathgroup at smc.vnet.net > To: mathgroup at smc.vnet.net > Subject: [mg22026] [mg21988] How do I force Log[Exp[x]]=x > > > For real x, Log[Exp[x]]=x. For general complex x > Mathematical leaves this expression unevaluated. I > have tried Log[Exp[x/;Im[x]=0]], but this give a result > of 0. > > How do I tell Mathematica that I want the expression > simplied for real x ? Thanks for any help. > -- > Bart Killam Work: 919-677-8000 x7538 > SAS Institute Inc. Fax: 919-677-8123 > SAS Campus Dr., R5115 Email: sasrbk at unx.sas.com > Cary NC 27513-8000 > >