Re: Integral giving complex answer
- To: mathgroup at smc.vnet.net
- Subject: [mg59274] Re: [mg59251] Integral giving complex answer
- From: Curtis Osterhoudt <gardyloo at mail.wsu.edu>
- Date: Thu, 4 Aug 2005 02:07:57 -0400 (EDT)
- References: <200508030519.BAA06368@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, David,
The Student Version 5.1.1.0 of Mathematica gives exactly the
ArcTan formula you want. Do you perhaps have some value already stored
in x?
Curtis O.
David Sagan wrote:
>Hello:
>
>I am tring to do simple integrals but I am running into problems in that
>Mathematica gives the answer using complex numbers. For example,
>Integrate[1/(1 + 5x^2), x] gives a result in terms of logarithms of a
>complex argument instead of the usual arctan formula. If I integrate
>something like Integrate[1/(1 + a x^2), x] I get the answer in the form
>I want using the arctan.
>
>My question is how to avoid getting the answer to Integrate[1/(1 +
>5x^2), x] in terms of complex logarithms. I know I could just integrate
>1/(1 + a x^2) and substitute a -> 5 later but in actuality I am dealing
>with more complex integrals and it would be helpful if I did not have to
>be making such substitutions.
>
> -- Thanks for any help, David Sagan
>
>
>
>
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- References:
- Integral giving complex answer
- From: David Sagan <dcs16@cornell.dot.edu>
- Integral giving complex answer