Question
- To: mathgroup at smc.vnet.net
- Subject: [mg46433] Question
- From: jjaeckel <jjaeckel at ix.urz.uni-heidelberg.de>
- Date: Wed, 18 Feb 2004 00:36:57 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hi!
I have a question about Integrate:
If I want to compute a completely real integral, e.g.
Integrate[(2*p^2*q^2*y^2 + p^3*q*y - p^2*q^2 + p*q^3*y + q^4)*1/(q^2)*1/(
q^2 + 2*p*q*y + p^2) - 1, {y, -1, 1}, {q, 0, ?}]
I quite often get a complex result, e.g. in this case
(for Mathematica 5.0)
(-\Pi^2+8*Log[-p]+8*Log[p])/(8*Sqrt[1/(p^2)])
Moreover, in Version 4.2 seems to produce a different result. E.g. if I
evaluate the above result for p=1 I get
-(1/8)*Pi*(-8*I+Pi)
but if I do the same calculation using Mathematica 4.2 I get
-(1/2)*Pi*(I+Pi)
What did I do wrong?
Sorry if this question isn't new...
Greetings
Joerg