force variable to be real

*To*: mathgroup at smc.vnet.net*Subject*: [mg91736] force variable to be real*From*: phillman5 <PHILLMAN5 at gmail.com>*Date*: Sun, 7 Sep 2008 05:33:03 -0400 (EDT)

How do you force variables to be real? I have w:=x + I 2 x z, and y:=Re[w] and want the derivative of y wrt x, x and z are Real D[y, x] gives Re'[x] - 2 z Im'[x z] where I'd expect just 1. Or I need to evaluate Re[w] forcing x and z to be real, then take the derivative. Thank you for any help Paul

**Follow-Ups**:**Re: force variable to be real***From:*Benjamin Reedlunn <breedlun@umich.edu>

**Re: force variable to be real***From:*"peter lindsay" <pl.0@me.com>