See <http://groups.google.com/group/es.ciencia.matematicas/browse_frm/thread/efec149d26050126/94dcd222ada58ab7> in Spanish. David ----- Original Message ----- From: "N. J. A. Sloane" <njas@research.att.com> To: <math-fun@mailman.xmission.com>; <njas@research.att.com> Sent: Monday, February 25, 2008 04:05 Subject: [math-fun] help needed with a definite integral

Can anyone help with following integral, which arises in computing the average distance between two random points in a unit square? (Maple and Mathematica can't do it, at least the versions that I have.)

Let h = 1/2, to save space.

Int_{x = 0..h} Int_{r=-h-x..h-x} Int_{y=0..h} Int_{s=-h-y..h-y} sqrt(r^2+s^2) dx dr dy ds

A numerical value would be fine - and a method - there are several other integrals that are of interest.

Thanks! Neil

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