The function
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which does not have a local maximum at (0, 0), despite criteria commonly touted in the second half of the 1800s which indicated the contrary.
Peano Surface
See also
Local MaximumExplore with Wolfram|Alpha
References
Fischer, G. (Ed.). Plate 122 in Mathematische Modelle aus den Sammlungen von Universitäten und Museen, Bildband. Braunschweig, Germany: Vieweg, p. 119, 1986.Leitere, J. "Functions." §7.1.2 in Mathematical Models from the Collections of Universities and Museums (Ed. G. Fischer). Braunschweig, Germany: Vieweg, pp. 70-71, 1986.Cite this as:
Weisstein, Eric W. "Peano Surface." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PeanoSurface.html