## #2496 simplify_sum simplifies incorrectly

None
closed
nobody
5
2013-02-08
2012-11-15
Anonymous
No

Maxima 5.28.0 http://maxima.sourceforge.net
using Lisp SBCL 1.0.55.0-abb03f9
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%o1) /Applications/MathApps/Maxima.app/Contents/Resources/maxima/share/maxima\ /5.28.0/share/solve_rec/simplify_sum.mac
(%i2) simplify_sum(sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, inf));

2
%pi
2 ---- - 4
%pi 2
(%o2) ---- + --------
128 128

But this is not right. The extra -1/32 is spurious.

(%i4) float(simplify_sum(sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, 100)));
(%o4) .1156594265749686
(%i5) float (simplify_sum(sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, inf)));

(%o5) .08440942657526591
(%i6) float(1/32);
(%o6) 0.03125

## Discussion

• Andrej Vodopivec - 2013-02-08
• status: open --> closed
• milestone: --> None

• Andrej Vodopivec - 2013-02-08

Fixed in git:

(%i3) simplify_sum(sum(1/((2n-1)^2(2n+1)^2(2n+3)^2), n, 0, inf)), ratsimp;
(%o3) 3
%pi^2/256