On Tuesday, April 26, 2016 at 7:41:44 AM UTC-7, Laurent Decreusefond wrote: > > > What does mean log(-1+e^(-2*t)) since the argument is negative ? >
For t<0 that expression takes real values, so there the answer even makes sense in a real setting. The answer is generally correct for complex values t. You have to be careful that log is a multi-valued function, though, so if you want to use this antiderivative to compute definite integrals, you have to take care that appropriate branches are chosen. Luckily, for t>0 the branch choice seems consistent, so: sage: I=integrate(exp(-2*t)/(1-exp(-2*t)),t) sage: (I(t=2)-I(t=1)).n() 0.0634640055214862 looks like a reasonable answer. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
