Opened 5 years ago
Last modified 5 years ago
#18599 new defect
Maxima integral wrong
Reported by: | kcrisman | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-6.8 |
Component: | calculus | Keywords: | |
Cc: | rws, nbruin | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | Reported upstream. No feedback yet. | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
See
- https://groups.google.com/forum/#!topic/sage-devel/GX-hYs0grdE
- https://groups.google.com/forum/#!topic/sage-devel/PSWsQPl1TBA
sage: from sage.symbolic.integration.external import maxima_integrator sage: maxima_integrator(sqrt(cot(x)^2),x) -1/2*log(tan(x)^2 + 1) + log(tan(x)) sage: maxima_integrator(cot(x),x) log(sin(x)) sage: maxima_integrator(sqrt(cot(x)^2),x,pi/4,3*pi/4) 0 sage: maxima_integrator(cot(x),x, pi/4,3*pi/4) 0 sage: f(x) = maxima_integrator(sqrt(cot(x)^2),x) sage: f(pi/4) -1/2*log(2) sage: f(3*pi/4) I*pi - 1/2*log(2)
But that is wrong, as this function is nonnegative and usually positive. The problem is in Maxima.
(%i1) domain:complex; (%o1) complex (%i2) sqrt(cot(x)^2); 2 (%o2) sqrt(cot (x)) (%i3) integrate(sqrt(cot(x)^2),x,%pi/4,%pi/4*3); (%o3) 0 (%i4) integrate(sqrt(cot(x)^2),x); 2 log(tan (x) + 1) (%o4) log(tan(x)) - ---------------- 2
Reported upstream at bug 2971.
Change History (2)
comment:1 Changed 5 years ago by
- Cc nbruin added
- Description modified (diff)
- Report Upstream changed from Not yet reported upstream; Will do shortly. to Reported upstream. No feedback yet.
comment:2 Changed 5 years ago by
- Description modified (diff)
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