[Date Index] [Thread Index] [Author Index]

Re: Solutions of an equation under complex form

• To: mathgroup at smc.vnet.net
• Subject: [mg54618] Re: Solutions of an equation under complex form
• From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
• Date: Thu, 24 Feb 2005 03:21:21 -0500 (EST)
• Organization: Uni Leipzig
• References: <cvc7un$qqr$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

Solve [x^2 + x + 1 == 0, x] /. (a_ -> b_) :> a -> ComplexExpand[b]

Regards
  Jens

"Michaël Monerau" <mmonerau at gmail.com> schrieb im Newsbeitrag 
news:cvc7un$qqr$1 at smc.vnet.net...
> Hello,
>
> I'm running into a little problem under Mathematica 5.0 but I'm sure
> people here will just take it as "too easy", but, well :) I just want
> the solutions of the equation :
>
> x^2 + x + 1 == 0
>
> under their complex form.
>
> So, I type :
>
> Solve [x^2 + x + 1 == 0, x]
>
> But I unfortunately get :
> { { {x -> -(-1)^(1/3) }, { x -> (-1)^(2/3) } } }
>
> And I'd prefer to obtain the more "readable" form :
> -1/2 + I*1/2*Sqrt[3], -1/2 - I*1/2*Sqrt[3]
>
> that I would get under another system for instance. What special function
> should I call to get this form under Mathematica ?
>
> Thanks for any help
> -- 
> Michaël Monerau
> -= JJG =-
>