Re: How to find and plot real roots?
- To: mathgroup at smc.vnet.net
- Subject: [mg33576] Re: How to find and plot real roots?
- From: Tim Brophy <timbrophy at eircom.net>
- Date: Mon, 1 Apr 2002 02:02:09 -0500 (EST)
- References: <a86kjt$ju3$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
On 3/31/02 11:24 AM, in article a86kjt$ju3$1 at smc.vnet.net, "Chitchanok
Carlen" <anok at earthlink.net> wrote:
> 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?
>
> Thanks.
>
In "The Beginner's Guide to Mathematica" by Jerry Glynn and Theodore Gray ,
you will find your question answered. Start your notebook with
Needs["Miscellaneous`RealOnly`"]; Now you can do what you like.
Solve[x^3 == -1, x]
Nonreal::"warning": "Nonreal number encountered."
{{x -> -1}, {x -> Nonreal}, {x -> Nonreal}}
And
Plot[x^(1/3)*(x + 3)^(2/3), {x, -5, 5}];
Will give you the graph you want.
Tim Brophy