Mathematician:Karl Theodor Wilhelm Weierstrass

Mathematician
German mathematician whose main work concerned the rigorous foundations of calculus.

Known as "the father of modern analysis".

Champion beer-drinker and expert fencer.

Nationality
German

History

 * Born: 31 Oct 1815, Ostenfelde, Westphalia (now Germany)
 * Died: 19 Feb 1897, Berlin, Germany

Achievements

 * Pioneered the $\epsilon-\delta$ definition of continuity.
 * Was able thereby to formulate proofs of the Bolzano-Weierstrass Theorem (which had been proved earlier, independently of Weierstrass, by ), the Intermediate Value Theorem and the Heine-Borel Theorem.
 * Made significant advancements in the field of calculus of variations.

Theorems and Definitions

 * Weierstrass Approximation Theorem
 * Weierstrass-Casorati Theorem (with )
 * Weierstrass's Elliptic Functions
 * Weierstrass-Erdmann Corner Conditions
 * Weierstrass Function
 * Weierstrass M-Test
 * Weierstrass Preparation Theorem
 * Weierstrass Factorization Theorem
 * Weierstrass Intermediate Value Theorem (also known as Bolzano's Theorem for )
 * Weierstrass Extreme Value Theorem
 * Weierstrass Substitution
 * Bolzano-Weierstrass Theorem (independently of )
 * Enneper-Weierstrass Parameterization (with )
 * Hermite-Lindemann-Weierstrass Theorem (with  and )
 * Sokhotski-Weierstrass Theorem (with )
 * Stone-Weierstrass Theorem (with ) (a generalization of the Weierstrass Approximation Theorem)

Books and Papers

 * 1856: Theorie der Abelschen Funktionen
 * 1894: Abhandlungen-1
 * 1897: Abhandlungen-2
 * 1902: Vorl. ueber die Theorie der Abelschen Transcendenten
 * 1915: Abhandlungen-3
 * 1927: Vorl. ueber Variationsrechnung
 * 1927: Vorl. ueber Variationsrechnung

Notable Quotes

 * A mathematician who is not also something of a poet will never be a complete mathematician.
 * -- Quoted in : They Say: What Say They? : Let Them Say


 * The infinite emptiness and boredom of those years would have been unendurable without the hard work that made me a recluse -- even if I was rated rather a good fellow by the circle of my friends among the Junkers, lawyers, and young officers of the community ... The present offered nothing worth mentioning, and it was not my custom to speak of the future.

Critical View

 * You should study with Weierstrass in Berlin; he is the master of us all.
 * -- to