#15504: Possible integration error
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Reporter: ppurka | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.1
Component: calculus | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
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Description changed by ppurka:
Old description:
> From google spreadsheet which no one reads `X-(`
>
> A simple integration error.
> {{{
> sage: integrate(log(1+x)/x,x)
> log(x + 1)*log(-x) + polylog(2, x + 1)
> sage: integrate(log(1+x)/x,x,0,1)
> -1/6*pi^2 + I*pi*log(2) + polylog(2, 2)
> }}}
>
> Both of which are wrong according to 2.728 of Gradshteyn & Ryzhik.
> Actually the second example is obviously wrong since the integration is a
> real function over a real interval.
>
> Should I report the error to Maxima? That seems to be the source.
New description:
From google spreadsheet which no one reads `X-(`
A simple integration error.
{{{
sage: integrate(log(1+x)/x,x)
log(x + 1)*log(-x) + polylog(2, x + 1)
sage: integrate(log(1+x)/x,x,0,1)
-1/6*pi^2 + I*pi*log(2) + polylog(2, 2)
}}}
Both of which are wrong according to 2.728 of Gradshteyn & Ryzhik.
Actually the second example is obviously wrong since the integration is a
real function over a real interval.
Should I report the error to Maxima? That seems to be the source.
PS:
1. The "I" above is not me (ppurka)
2. I am done scrounging through the google spreadsheet for bugs, for now.
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Ticket URL: <http://trac.sagemath.org/ticket/15504#comment:1>
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