ComplexExpand confusion

*To*: mathgroup at smc.vnet.net*Subject*: [mg60109] ComplexExpand confusion*From*: mike_in_england2000 at yahoo.co.uk*Date*: Sat, 3 Sep 2005 02:05:58 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi The Mathematica help system says that "ComplexExpand[expr] expands expr assuming that all variables are real." which is fine and explains why expressions such as ComplexExpand[Conjugate[x +I y]] work.All seems obvious so far. What is confusing me though is why does ComplexExpand[(-1)^(1/4)] give the result (1 + I)/Sqrt[2] I know this the correct result but in the expression (-1)^(1/4) there are no variables. The numbers involved are real so what on earth is ComplexExpand doing? Is this a stupid question? Should I have drank more coffee before posting this. Thanks Mike