Re: Integral giving complex answer
- To: mathgroup at smc.vnet.net
- Subject: [mg59280] Re: [mg59251] Integral giving complex answer
- From: Pratik Desai <pdesai1 at umbc.edu>
- Date: Thu, 4 Aug 2005 02:08:02 -0400 (EDT)
- References: <200508030519.BAA06368@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
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 > > > I works fine on my Ver 5.1.1.0 Win Xp Integrate[1/(1 + 5x^2), x] >>\!\(ArcTan[\@5\ x]\/\@5\) Try reloading with a fresh kernel Best regards -- Pratik Desai Graduate Student UMBC Department of Mechanical Engineering Phone: 410 455 8134
- References:
- Integral giving complex answer
- From: David Sagan <dcs16@cornell.dot.edu>
- Integral giving complex answer