Trouble computing conjugates

*To*: mathgroup at smc.vnet.net*Subject*: [mg88515] Trouble computing conjugates*From*: Roy <sarahroy at earthlink.net>*Date*: Wed, 7 May 2008 07:07:41 -0400 (EDT)

I'm having trouble getting mathematica to compute complex conjugates of some fairly simple expressions: If I type the following: $Assumptions = {g \[Element] Reals, f \[Element] Reals} u1 = f + \[ImaginaryI] g u2 = f - \[ImaginaryI] g Then the command: Refine[Conjugate [c1 u1]] returns: f - \[ImaginaryI] g) Conjugate[c1] and the command: Refine[Conjugate[c1 u1 + u2]] returns: f + \[ImaginaryI] g + (f - \[ImaginaryI] g) Conjugate[c1] as I would expect. But the command: Refine[Conjugate[c1 u1 + c2 u2]] returns: Conjugate[c2 (f - \[ImaginaryI] g) + c1 (f + \[ImaginaryI] g)] i.e. it refuses to distribute the complex conjugate throughout the expression. What I would like it to tell me is: (f + \[ImaginaryI] g) Conjugate[c2] + (f - \[ImaginaryI] g) Conjugate[c1] The closest I have been able to come to getting what I want is by using: ComplexExpand[Refine[Conjugate[ c1 u1 + c2 u2]], {c1, c2}] but this separates c1 and c2 into their real and imaginary parts. The above expressions are much simpler than the ones I REALLY want Mathematica's help in simplifying. If I use this ComplexExpand command, then I'm going to have to recombine them into complex numbers again, which would be very very bad. Thanks, Roy

**Follow-Ups**:**Re: Trouble computing conjugates***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>

**Re: Trouble computing conjugates***From:*Murray Eisenberg <murray@math.umass.edu>