Incorrect integral from Maxima
|Reported by:||kcrisman||Owned by:||burcin|
|Report Upstream:||Fixed upstream, in a later stable release.||Work issues:|
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.
Change History (18)
comment:9 Changed 4 years ago by kcrisman
- Report Upstream changed from Not yet reported upstream; Will do shortly. to Fixed upstream, but not in a stable release.
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