Services & Resources / Wolfram Forums / MathGroup Archive

MathGroup Archive 2011

[Date Index] [Thread Index] [Author Index]

Search the Archive

Integration error? Integrate[1/(x^3-1)]?

  • To: mathgroup at
  • Subject: [mg121702] Integration error? Integrate[1/(x^3-1)]?
  • From: Travis Ayres <trayres at>
  • Date: Mon, 26 Sep 2011 04:16:18 -0400 (EDT)
  • Delivered-to:

The indefinite integral of 1/(x^3-1) with respect to x.
In input form, put into Mathematica 8:
Integrate[1/(x^3 - 1), x]
Gives result:
-(ArcTan[(1 + 2*x)/Sqrt[3]]/Sqrt[3]) + (1/3)*Log[1 - x] - (1/6)*
  Log[1 + x + x^2]

Computing online with the Wolfram integrator:^3-1%29&random=false
-(ArcTan[(1 + 2*x)/Sqrt[3]]/Sqrt[3]) + Log[-1 + x]/3 - Log[1 + x +

Look at the (1/3)*Log[1-x] term.
Mathematica 8 gives me Log[1-x], the online integrator gives the
answer Log[x-1].
The answers are exactly the same in all other terms. I ran across this
because I was trying the tutorials, and I noticed my answer was
different than the result in the tutorial even.

Is this an error?
Thanks all!

  • Prev by Date: Re: Bug with Sequence and Assignment by Part...
  • Next by Date: Re: Count Number of Iteration [FindRoot]
  • Previous by thread: Re: More FinancialData glitches
  • Next by thread: Re: Integration error? Integrate[1/(x^3-1)]?