On 2014-07-22, Craig E Larson <clar...@vcu.edu> wrote: > I am getting an error that I don't understand for the following definite > integral. > > sage: integral(sqrt(1+(9*cos(3*x)^2)),0,pi/2) > > This is definitely real on its domain and under the square-root is always > positive. Nevertheless, I get the error: > > "RuntimeError: ECL says: Error executing code in Maxima: sign: argument > cannot be imaginary; found %i" > > I can get an answer using "numerical_integral". But I would like to know if > I'm missing something.
What version of Sage? In Sage 6.3.beta6 I get an error too, but it seems to indicate a bug in Maxima: sage: integral(sqrt(1+(9*cos(3*x)^2)),0,pi/2) #0: intfudu(exp=%e^-(%i*?new\-var\-10199)*sqrt((22*%e^-(2*%i*?new\-var\-10199)+9*%e^-(4*%i*?new\-var\-10199)+9)*%e^(...,%voi=?new\-var\-10199) #1: extra_integrate(q=%e^-(%i*?new\-var\-10199)*sqrt((22*%e^-(2*%i*?new\-var\-10199)+9*%e^-(4*%i*?new\-var\-10199)+9)*%e^(...,x=?new\-var\-10199) --------------------------------------------------------------------------- RuntimeError Traceback (most recent call last) <ipython-input-4-21cb4ede47a7> in <module>() .... > > Thanks. > -- 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 sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
