Re: How do I force Log[Exp[x]]=x
- To: mathgroup at smc.vnet.net
- Subject: [mg22025] Re: [mg21988] How do I force Log[Exp[x]]=x
- From: Andrzej Kozlowski <andrzej at platon.c.u-tokyo.ac.jp>
- Date: Fri, 11 Feb 2000 02:38:08 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In Mathematica 4 In[3]:= Simplify[Log[Exp[x]], Element[x, Reals]] Out[3]= x In earlier versions: In[4]:= PowerExpand[Log[Exp[x]]] Out[4]= x > From: sasrbk at unx.sas.com (Bart Killam) To: mathgroup at smc.vnet.net > Organization: SAS Institute > Date: Thu, 10 Feb 2000 02:25:32 -0500 (EST) > To: mathgroup at smc.vnet.net > Subject: [mg22025] [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 >