Peano surface
In mathematics, the Peano surface is the graph of the two-variable function
It was proposed by Giuseppe Peano in 1899 as a counterexample to a conjectured criterion for the existence of maxima and minima of functions of two variables.[1][2]
The surface was named the Peano surface (German: Peanosche Fläche) by Georg Scheffers in his 1920 book Lehrbuch der darstellenden Geometrie.[1][3] It has also been called the Peano saddle.[4][5]
Models[edit]
Models of Peano's surface are included in the Göttingen Collection of Mathematical Models and Instruments at the University of Göttingen,[11] and in the mathematical model collection of TU Dresden (in two different models).[12] The Göttingen model was the first new model added to the collection after World War I, and one of the last added to the collection overall.[6]