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From: "Joerg Buchholz" <buchholz@hs-bremen.de>
Newsgroups: comp.soft-sys.matlab
Subject: Re: int in R2008b, same integral?
Date: Thu, 15 Jan 2009 15:52:01 +0000 (UTC)
Organization: Hochschule Bremen
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The bug has not been fixed in R2009a.

"Joerg Buchholz" <buchholz@hs-bremen.de> wrote in message <gi0aqa$e0u$1@fred.mathworks.com>...
> "Georgios" 
> > If you integrate using a bounded range, say -1..1, then you should get an answer of pi for both.  
> 
> 
> Unfortunately, this is not the case:
> 
> >> int ('sqrt(1/(1-x^2))', -1, 1)
> Warning: Explicit integral could not be found. 
> > In sym.int at 64
>   In char.int at 9
>  
> ans =
>  
> int((-1/(x^2 - 1))^(1/2), x = -1..1)
> 
> Even explicitely restricting the range of x does not help:
> 
> >> evalin (symengine, 'assume (x<1)');
> >> evalin (symengine, 'assumeAlso (x>-1)');
> >> evalin (symengine, 'getprop(x)')
>  
> ans =
>  
> (-1, 1)
>  
> >> int ('sqrt(1/(1-x^2))', -1, 1)
> Warning: Explicit integral could not be found. 
> > In sym.int at 64
>   In char.int at 9
>  
> ans =
>  
> int((-1/(x^2 - 1))^(1/2), x = -1..1)