Re: Separating real part and imaginary part from each other

*To*: mathgroup at smc.vnet.net*Subject*: [mg101240] Re: Separating real part and imaginary part from each other*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Sat, 27 Jun 2009 06:06:26 -0400 (EDT)*References*: <h2295a$hoj$1@smc.vnet.net>

Hi, f[z_] := (a*z + b)/(c*z + d) f[x + I*y] // {Re[#], Im[#]} & // ComplexExpand ? Regards Jens Alexander wrote: > Hi, > > suppose I have the expression > > f(z) = (a*z+b) / (c*z+d) with z=x+I*y > > I did the calculation by hand and was able to separate real part fom > imag. part to obtain something like this: > > g=f(x+I*y) = Re(g) + I * Im(g) > > But I don't know how to do this in Mathematica. I tried FullSimplify, > Together, Apart, they didn't work. Can you help me? > > Alexander >