 
 
 
 
 
 
Re: Re: a first-time user question
- To: mathgroup at smc.vnet.net
- Subject: [mg39402] Re: [mg39376] Re: a first-time user question
- From: Jan Mangaldan <hokenjan at yahoo.com>
- Date: Fri, 14 Feb 2003 03:18:18 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Better yet: 
In[1]:= realCubeRoot[z_]:= Sign[z] Abs[z]^(1/3) 
In[2]:= Plot[(realCubeRoot[x])^2, {x,-1,0}] 
Hope this helps. 
 
                                                                                                     Jan M. (^_^) 
 Nilton Volpato <nilton.volpato at ig.com.br> wrote: Use:
Needs["Miscellaneous'RealOnly'"]
Plot[x^(2/3), {x,-1,0}]
This will work.
-- Nilton
"Ye Hu" wrote in message news:...
> I have a simple (supposedly) question...
> 
> I used the following command to draw a plot, but Mathematica could not run
> properly.
> 
> Plot[x^(2/3),{x,-1,0}]
> 
> 
> I know the problem is about calculating (-1)^(1/3) in mathematica. Although
> (-1)^(1/3) = -1,
> mathematica tries to calculate it numerically and gives complex results
> 0.5+0.8i
> How to solve this problem and restrict the solution to be only real numbers?
> 
> Thanks very much.

