Re: Real and Imaginary Parts of complex functions
- To: mathgroup at smc.vnet.net
- Subject: [mg129945] Re: Real and Imaginary Parts of complex functions
- From: Szabolcs HorvÃt <szhorvat at gmail.com>
- Date: Wed, 27 Feb 2013 03:08:18 -0500 (EST)
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On 2013-02-26 06:09:00 +0000, Brentt said: > Hello, > > I was wondering why this works > > IN[]:= Refine[Re[x + y I], Element[x , Reals] && Element[y , Reals]] > > Out[]:= x > > But this does not > > In[]:= Refine[Re[1/(x + y I)], Element[x , Reals] && Element[y , Reals]] > > Out[]:= Re[1/(x + y I)] > > > > Is there a nice built in way to get the real and imaginary parts of a > complex function? You can use ComplexExpand for this. In[8]:= ComplexExpand[Re[1/(x + y I)]] Out[8]= x/(x^2 + y^2) See also http://mathematica.stackexchange.com/q/9340/12 and the links within.