-
-
Notifications
You must be signed in to change notification settings - Fork 660
Closed
Description
This is fixed now and needs a doctest:
From #sage-devel:
Boulemans left the chat room. (Read error: Connection reset by peer)
[11:58am] Boule joined the chat room.
[11:58am] Boule: (laptop shutdown due to power supply)
[11:59am] Boule: e, T, w = var("e T w"); assume(1 = e^2)>0; integrate(cos(w+T)/(1+e*cos(T))^2,T,0,2*pi) should give -2*pi e cos w/(1-e^2)^3/2 instead of 0
[11:59am] Boule: can someone help?
[12:00pm] wjp: yeah, sage seems to have some trouble with this integral. You could try http://groups.google.com/group/sage-support since the right people don't seem to be here currently
[12:00pm] Boule: ok, thanx
[12:08pm] kcrisman: By the way, I just tried this and get a hang in Maxima. Can you type the exact commands which lead to an answer of 0?
[12:08pm] kcrisman: If I plug something (.5, .75) in for e in Maxima in Sage, I do get zero as an output.
[12:12pm] Boule: don't know maxima, but with numerical values for e and w at wolfram-alfa, it gives something different than 0
[12:13pm] wjp: *nod* maple gives non-zeros too
[12:13pm] kcrisman: Can you give the *exact* sequence of commands which yield zero in Sage itself?
[12:14pm] Boule: e = var('e')
[12:14pm] Boule: T = var('T')
[12:14pm] Boule: w = var('w')
[12:14pm] baali1 joined the chat room.
[12:14pm] baali left the chat room. (Quit: Leaving.)
[12:15pm] Boule: assume(1-e^2>0)
[12:15pm] Boule: integrate(cos(w+T)/(1+e*cos(T))^2,T,0,2*pi)
[12:15pm] kcrisman: Okay, that's what I thought.
[12:16pm] kcrisman: Okay, it takes a while but I do get 0.
Component: calculus
Author: Ralf Stephan
Branch: d4b0db5
Reviewer: Travis Scrimshaw
Issue created by migration from https://trac.sagemath.org/ticket/8728