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unusual facts about Weierstrass



Calculus of variations

Other valuable treatises and memoirs have been written by Strauch (1849), Jellett (1850), Otto Hesse (1857), Alfred Clebsch (1858), and Carll (1885), but perhaps the most important work of the century is that of Weierstrass.

Cantor's first uncountability proof

Cantor biographer Joseph Dauben argues that "local circumstances" refers to the influence of Leopold Kronecker, Weierstrass' colleague at the University of Berlin.

Gyula Vályi

After qualifying as a teacher of mathematics and physics Vályi was awarded a scholarship to allow him to study for two years at the University of Berlin, where the remarkable mathematics team of Kummer, Borchardt, Weierstrass and Kronecker were lecturing.

Karl Weierstrass

He also helped devise the Weierstrass–Erdmann condition, which gives sufficient conditions for an extremal to have a corner along a given extrema, and allows one to find a minimizing curve for a given integral.

Mergelyan's theorem

After Weierstrass and Runge, many mathematicians (in particular Walsh, Keldysh, and Lavrentyev) had been working on the same problem.

Uniform convergence

Under the influence of Weierstrass and Bernhard Riemann this concept and related questions were intensely studied at the end of the 19th century by Hermann Hankel, Paul du Bois-Reymond, Ulisse Dini, Cesare Arzelà and others.


see also