#11164: Integral of sin(x)/x gives false result.
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Reporter: benreynwar | Owner: burcin
Type: defect | Status: needs_info
Priority: major | Milestone:
Component: calculus | Keywords:
Work_issues: | Upstream: Fixed upstream, in a later stable
release.
Reviewer: | Author:
Merged: | Dependencies:
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Comment(by kcrisman):
This is the previous version (5.25.1):
{{{
(%i5) integrate(sin(x)/x,x,-1/1000000,1/1000000);
(%o5) %i*gamma_incomplete(0,-%i/1000000)-%i*gamma_incomplete(0,%i/1000000)
}}}
W|A agrees that this is about `-pi`. (To be precise, `2*Si(1/10^6)-pi`.)
{{{
(%i4) display2d:false;
(%o4) false
(%i5) integrate(sin(x)/x,x);
(%o5) -(%i*gamma_incomplete(0,%i*x)-%i*gamma_incomplete(0,-%i*x))/2
}}}
Here is the issue; this function may or may not be the same as the sine
integral. The problem seems to be that although Maxima has the sine
integral (`expintegral_si`), it isn't really connected with the rest of
Maxima (?).
What do you think a good solution to this is? I suppose we could open a
ticket for it on the Maxima site, but I'm not sure whether the `Si` there
is robust enough to handle all this yet.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11164#comment:5>
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