symbolic complex expressions

*To*: mathgroup at smc.vnet.net*Subject*: [mg53637] symbolic complex expressions*From*: frankdeicke at gmx.de (Frank)*Date*: Fri, 21 Jan 2005 06:35:44 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I've 2 question with mathematica using symbolic complex expressions. - Is there a possibility to make from i.e. |x + I y| -> sprt(x^2+y^2) if x and y are Real. Abs[] doesn't work? - You've a fraction like this x/(x + I y) and you want to eliminate the complex expression in the denominator. i.e. doing something like this: x/(x + Iy)*(x - I y)/(x - I y) -> (x^2 - I x y)/(x^2+y^2) How do you do this with mathematica? Thanks, Frank

**Follow-Ups**:**Re: symbolic complex expressions***From:*Murray Eisenberg <murray@math.umass.edu>