1. [Cauchy–Riemann equations][1] were known to d'Alembert and Euler.

2. Two-dimensional [Voronoi diagram][2]s were used by Descartes, three-dimensional - by Dirichlet. Also should be noted, that this construction has several other names in physics: Wigner–Seitz cells, Thiessen polygons.



  [1]: https://en.wikipedia.org/wiki/Cauchy%E2%80%93Riemann_equations
  [2]: https://en.wikipedia.org/wiki/Voronoi_diagram