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