Re: How to find and plot real roots?
- To: mathgroup at smc.vnet.net
- Subject: [mg33573] Re: [mg33566] How to find and plot real roots?
- From: BobHanlon at aol.com
- Date: Mon, 1 Apr 2002 02:02:05 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 3/31/02 4:19:00 AM, anok at earthlink.net writes:
>How does one find the real root, for example:
>
>(-1)^(1/3) in Mathematica ?
>
>Also, I want to plot x^(1/3)*(x+3)^(2/3), but the fact that Mathematica
>doesn't
>know which roots to pick causes errors in the Plot function. How to force
>
>it to find real roots?
>
Select[Solve[x^3==-1,x], Element[x /. # , Reals]&]
{{x -> -1}}
-Abs[(-1)^(1/3)]
-1
Needs["Graphics`Colors`"];
Plot[Sign[x]*Abs[x^(1/3)*(x+3)^(2/3)],
{x,-5,2},
PlotStyle->Red];
Bob Hanlon
Chantilly, VA USA