Re: symbolic complex expressions

*To*: mathgroup at smc.vnet.net*Subject*: [mg53681] Re: [mg53637] symbolic complex expressions*From*: Hugh Walker <hwalker at gvtc.com>*Date*: Sat, 22 Jan 2005 03:52:27 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hello Frank: Abs[x+I y]//ComplexExpand x/(x+I y)//ComplexExpand On Friday, January 21, 2005, at 05:35 AM, Frank wrote: > 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 > > > ========== Hugh Walker Gnarly Oaks