[Maxima-bugs] [ maxima-Bugs-1167441 ] integrate pbs.?

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Bugs item #1167441, was opened at 2005-03-21 02:49
Message generated for change (Comment added) made by nobody
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Category: Share Libraries
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: integrate pbs.?

Initial Comment:
maxima chokes on integrate(1/(x**3+a*x**2+x),x); 
 
MuPAD, by comparison, gives an ans. in ca. 2 sec. 
 
maxima 5.9.1 
bld: 21/24 9/23/04 
host: i686 linux 
lisp Common, 19a 

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Comment By: Nobody/Anonymous (nobody)
Date: 2005-03-22 14:53

Message:
Logged In: NO 

Barton is correct.  My pb. was due to texmacs not passing 
the question forward.  Perhaps this whole thread should be 
deleated here.  

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Comment By: Barton Willis (willisbl)
Date: 2005-03-21 03:05

Message:
Logged In: YES 
user_id=895922

I didn't check these answers by hand, but I don't
see a problem.  Maybe you could send a copy
of your session, or explain why these antiderivatives
are wrong.

(%i1) integrate(1/(x**3+a*x**2+x),x);
Is a^2-4positive or negative?neg;
(%o1)
-log(x^2+a*x+1)/2-(a*atan((2*x+a)/sqrt(4-a^2)))/sqrt(4-a^2)+log(x)
(%i2) radcan(diff(%,x));
(%o2) 1/(x^3+a*x^2+x)
(%i3) integrate(1/(x**3+a*x**2+x),x);
Is a^2-4positive or negative?pos;
(%o3)
-(a*log((2*x-sqrt(a^2-4)+a)/(2*x+sqrt(a^2-4)+a)))/(2*sqrt(a^2-4))-log(x^2+a*x+1)/2+log(x)
(%i4) radcan(diff(%,x));
(%o4) 1/(x^3+a*x^2+x)

(%i5) build_info();
Maxima version: 5.9.1
Maxima build date: 7:34 9/24/2004
host type: i686-pc-mingw32
lisp-implementation-type: Kyoto Common Lisp
lisp-implementation-version: GCL 2.6.5

Barton

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