Monkey Saddle and its base

Monkey Saddle
Monkey Saddle is a mathematical surface which belongs to the class of saddle surfaces, and its name derives from the observation that a saddle for a monkey would require three depressions: two for the legs and one for the tail. The surface is defined by the equation z = x³ - 3xy² which can also be described parametrically: x(u, v) = u; y(u, v) = v and z(u, v) = u³-3uv².

Ahvisadul
Ahvisadul on matemaatiline pind, mis kuulub sadulpindade klassi ja ta saab oma nime sellest, et ahvil on vaja kolme süvendit, et ta saaks seda sadulat kasutada: kaks neist jalgade jaoks ja üks ahvi saba jaoks.
Ahvisadula valemiks on z = x³ - 3xy², mida saab anda edasi ka parameetriliste võrrandite abil: x(u, v) = u; y(u, v) = v ja z(u, v) = u³-3uv².