A Fubini Example

z = (x^2 - y^2) / (x^2 + y^2)^2 (from a paper in College Math. Journal (1998) by Hern, Long, and Long, who used it as an example related to Fubini's Theorem). In a rectangular plot the pieces do not touch properly at the z-axis.

Created by Wolfram Mathematica 6.0  (28 October 2007)