Is -1^(2/5) really undefined in R?

*To*: mathgroup at smc.vnet.net*Subject*: [mg69075] Is -1^(2/5) really undefined in R?*From*: Ben <ben.carbery at spam.me>*Date*: Tue, 29 Aug 2006 04:47:34 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Is -1^(2/5) really undefined in R? Mathematica seems to think so, I guess since it looks like a negative square root, but -1^(2/5) = (-1^2)^(1/5) = 1^(1/5) = 1 Is this correct mathematically? cheers, BC

**Follow-Ups**:**Re: Is -1^(2/5) really undefined in R?***From:*Murray Eisenberg <murray@math.umass.edu>

**Re: Is -1^(2/5) really undefined in R?***From:*János <janos.lobb@yale.edu>