[Maxima-bugs] [ maxima-Bugs-1579852 ] bad integral evaluation

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Bugs item #1579852, was opened at 2006-10-18 10:15
Message generated for change (Comment added) made by nobody
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Category: Lisp Core - Integration
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Mark Peloquin (incripshin)
Assigned to: Nobody/Anonymous (nobody)
Summary: bad integral evaluation

Initial Comment:
The following integral should evaluate to infinity:

 integrate(x/sqrt(1+x^4), x, 1, inf);

This should be obvious since it's essentially
integrating 1/x up to infinity, which diverges.  Do the
work if you like ... it diverges.

Maxima evaluates this to:
  log((2*sqrt(2)+3)/(24*sqrt(2)+34))/4

However, maxima can tell that this diverges:
  limit(integrate(x/sqrt(1+x^4), x), x, inf)

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Comment By: Nobody/Anonymous (nobody)
Date: 2006-10-22 07:53

Message:
Logged In: NO 


 In version 5.10.0 maxima gives the correct answer: 

(%i28) integrate(x/sqrt(1+x^4), x, 1, inf);

Integral is divergent -- an error.  Quitting. 

 To debug this try debugmode(true);

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Comment By: Raymond Toy (rtoy)
Date: 2006-10-21 12:41

Message:
Logged In: YES 
user_id=28849

What version?

5.10.0 says the integrate(x/sqrt(1+x^4),x,1,inf) is divergent.


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