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Re: Why does this lead to an answer with complex numbers?

• To: mathgroup at smc.vnet.net
• Subject: [mg71486] Re: Why does this lead to an answer with complex numbers?
• From: dh <dh at metrohm.ch>
• Date: Mon, 20 Nov 2006 06:34:28 -0500 (EST)
• References: <ejosmm$n3k$1@smc.vnet.net> <ejrmr9$97b$1@smc.vnet.net>

Hi Aaron,
you could e.g. subtract the constant imaginary part and use Chop to get 
rid of the residual small imaginary residual.
Daniel

aaronfude at gmail.com wrote:
> Hi,
> 
> Thanks for all the answers. They were all very useful, even though I
> have done my best to confuse everyone by leaving a beta in there which
> had nothing to do with the problem.
> 
> So I understand that the answer may be complex and the complex part is
> constant which is in a certain sense valid for a indefinite integral.
> But I very much need a real answer and I still can't quite extract.
> Consider the following:
> 
> \!\(\(\(\ \)\(Assuming[x > 0 && A > 0 && B > 0 && \ B < 1, \
>     FullSimplify[Integrate[Log[\@\(A^2 + x\^2\) - B*x\ ], \ x]]]\)\)\)
> 
> The answer that I get is correct, but not very useful since it is
> appears complex and I could find a way to determine the real part. Do
> you have any suggestions?
> 
> 
> Thank you!
> 
> Aaron Fude
>