Services & ResourcesWolfram ForumsMathGroup Archive

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

Re: Solutions of an equation under complex form

• To: mathgroup at smc.vnet.net
• Subject: [mg54535] Re: [mg54478] Solutions of an equation under complex form
• From: Pratik Desai <pdesai1 at umbc.edu>
• Date: Tue, 22 Feb 2005 04:24:15 -0500 (EST)
• References: <200502210844.DAA27204@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Michaël Monerau wrote:

>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
>  
>
Try This
y=x^2+x+1
s=Reduce[y==0,x]
s[[1]]//ComplexExpand
s[[2]]//ComplexExpand

hope this helps

Pratik Desai

• References:
  • Solutions of an equation under complex form
    • From: Michaël Monerau <mmonerau@gmail.com>