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Re: How do I force Log[Exp[x]]=x

• To: mathgroup at smc.vnet.net
• Subject: [mg22035] Re: How do I force Log[Exp[x]]=x
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Fri, 11 Feb 2000 02:38:16 -0500 (EST)
• Organization: Universitaet Leipzig
• References: <87tp95$5ia@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

there are so many ways

Log[Exp[x]] // PowerExpand

Simplify[Log[Exp[x]], Element[x, Reals]]

FullSimplify[Log[Exp[x]], Element[x, Reals]]

Regards
  Jens

Bart Killam wrote:
> 
>   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.