Re: Simplify[ {Re[Sqrt[-1 + eta^2]], Im[Sqrt[-1 + eta^2]]}, eta<1]
- To: mathgroup at smc.vnet.net
- Subject: [mg50631] Re: Simplify[ {Re[Sqrt[-1 + eta^2]], Im[Sqrt[-1 + eta^2]]}, eta<1]
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Wed, 15 Sep 2004 01:49:25 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <ci3ele$e41$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
FullSimplify[test, eta < 1 && eta > -1]
??
Regards
Jens
peteraptaker wrote:
>
> Have I missed something - my apologies if this is answered in a FAQ
> I want to make the simple Re and Im parts simplify properly?
>
> test =
> {Re[Sqrt[-1 + eta^2]], Im[Sqrt[-1 + eta^2]]}
>
> FullSimplify[test, eta > 1]
> gives*{Sqrt[-1 + eta^2], 0}
>
> But
> FullSimplify[test, eta < 1]
> gives
> {Re[Sqrt[-1 + eta^2]], Im[Sqrt[-1 + eta^2]]}
>
> Needs["Algebra`ReIm`"] does not seem to help
>
> Real numbers demonstrate what should happen:
> test) /. {{eta -> 0.1}, {eta -> 2}}
> {{0., 0.99498743710662}, {Sqrt[3], 0}}