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Re: Logical evaluation

• To: mathgroup at smc.vnet.net
• Subject: [mg82299] Re: Logical evaluation
• From: Peter Breitfeld <phbrf at t-online.de>
• Date: Wed, 17 Oct 2007 04:00:39 -0400 (EDT)
• References: <ff1pq1$91j$1@smc.vnet.net>

Michael Mandelberg schrieb:
> I can't figure out why the following does not evaulate to TRUE:
>
> In[100]:= \[ExponentialE]^(-\[ImaginaryI] x) + \[ExponentialE]^(\
> \[ImaginaryI] x) == 2 TrigToExp[Cos[x]]
>
> Out[100]= \[ExponentialE]^(-\[ImaginaryI] x) + \[ExponentialE]^(\
> \[ImaginaryI] x) ==
>  2 (\[ExponentialE]^(-\[ImaginaryI] x)/
>     2 + \[ExponentialE]^(\[ImaginaryI] x)/2)
>
> Any ideas?
>
> Michael Mandelberg
>
>
Wrap your In[100] in ComplexExpand, and you get the Result True.
Simplify also works.

Gruss Peter
-- 
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Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de