From: SourceForge.net <noreply@so...>  20060731 03:46:37

Bugs item #1044318, was opened at 20041010 21:40 Message generated for change (Comment added) made by robert_dodier You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1044318&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. >Category: Lisp Core  Integration Group: None Status: Open Resolution: None Priority: 5 Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: defint(1/(sin(x)^2+1),x,0,3*%pi) wrong Initial Comment: INTEGRATE(1/(SIN(x)^2+1),x,0,3*%PI) => 0 Since the integrand is everywhere >= 1/2, the integral cannot be zero  in fact integrate(1/(sin(x)^2+1),x,q,q+k*%pi) = k*pi/sqrt(2) (real q, integral k) Presumably defint is using the indefinite integral atan(2*tan(x)/sqrt(2))/sqrt(2) inappropriately.  >Comment By: Robert Dodier (robert_dodier) Date: 20060730 21:46 Message: Logged In: YES user_id=501686 Observed in 5.9.3cvs. I find defint(1/(sin(x)^2+1),x,0,3*%pi); => sqrt(2)*atan(sqrt(2)*tan(3*%pi))/2 sqrt(2)*atan(sqrt(2)*tan(0))/2 but then ratsimp(%) => 0 .  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1044318&group_id=4933 