Re: Radicals simplify

*To*: mathgroup at smc.vnet.net*Subject*: [mg106390] Re: Radicals simplify*From*: Peter Breitfeld <phbrf at t-online.de>*Date*: Mon, 11 Jan 2010 05:31:21 -0500 (EST)*References*: <hic37h$5ef$1@smc.vnet.net>

"francix" wrote: > Hi, > I am using Matematica 7 and need some help with Radicals. > > If I do > Simplify[(x^4 y^3)^(1/4), x >= 0] I correctly have > > x (y^3)^(1/4) > > But If I do > > Simplify[(x^6 y^3)^(1/4), x >= 0] I get > > (x^6 y^3)^(1/4) and not the correct answer x(x^2 y^3)^(1/4) > > Thanks in advanced. expr=(x^6 y^3)^(1/4); You may use Refine instead of Simplify: Refine[expr,x>=0] Out= x^(3/2) (y^3)^(1/4) Or, because you know that all variables are non negative, you may use PowerExpand: PowerExpand[expr] Out= x^(3/2) y^(3/4) But I think you can't get the result x(x^2 y^3)^(1/4) -- _________________________________________________________________ Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de