# Karl Weierstrass

Date of Birth: 10/31/1815

Age: 81

Place of birth: Ennigerloh

Citizenship: Germany

**Background**

Born in Ostenfeld, a suburb of Ennigerloh, North Rhine - Westphalia, in the officer`s family.

1834: graduated with honors from high school in Paderborn and at the insistence of his father, he entered the Law Faculty of the University of Bonn. After studying for 4 years, during which, instead of law Weierstrass intensively studied mathematics, he dropped out and enrolled in the Academy of Munster.

1840: prepared the examination paper on the theory of elliptic functions, which already contained the rudiments of his future discoveries.

1841: the new work Weierstrass established: if the sequence of analytic functions which converges uniformly within a certain area (ie every closed circle in the domain), the limit of the sequence - also an analytic function. There is a key condition for the uniform convergence; this concept and strict convergence theory has become one of the most important contributions to the study of Weierstrass analysis.

1842: at the end of the Academy received a teacher in a provincial Catholic preschools, where he worked for 14 years. Skills teacher Weierstrass further help to become a better teacher of German and rare free time (usually at night) he used to mathematical research. In addition to mathematics, he led there lessons in physics, botany, geography, history, German, calligraphy and gymnastics.

1854: published a paper on Abelian functions, for which the University of Konigsberg immediately awards him the degree of Doctor honoris causa (honorary doctorate without defending a thesis). Dirichlet sends a rave review by which Weierstrass was awarded the title of senior teachers and long time we ask for a sabbatical.

Rest it is used for the preparation of yet another brilliant article (1856). Alexander von Humboldt helped get Weierstrass first professor of the Industrial Institute in Berlin, and after a couple of months - an extraordinary professor at the University of Berlin. At the same time he was elected a member of the Berlin Academy of Sciences. University of Berlin, he gave 40 years of his life.

Since the late 1850s, international fame Weierstrass growing rapidly. These he owes the excellent quality of his lectures. Here is a list of the subject matter of courses:

Introduction to the theory of analytic functions, including the theory of real chisel.Teoriya elliptic functions, applications of elliptic functions to problems in geometry and mechanics.

The theory of Abelian integrals and functions.

Calculus of Variations.

Health Weierstrass poor - affects the constant fatigue in his younger years. In 1861, during a speech he began a violent attack of vertigo. and I had to interrupt the lecture. More Weierstrass never lectured standing - he always sat, and one of the best students wrote for him on the board.

1861: elected to the Bavarian Academy of Sciences.

1864: appointed full professor.

1868: elected a corresponding member of the Paris Academy of Sciences.

1870: acquainted with twenty Sofia Kovalevskaya came to Berlin for the preparation of the dissertation. Tender feelings for his Weierstrass Sonja has carried through all his life (he never married). Weierstrass Kovalevskaya helps to choose the topic of the dissertation and the method of approach to the solution in the future it regularly advises on complex analysis of the issues, assists in the preparation of scientific recognition.

After defending his thesis Kovalevskaya had gone on writing teacher answers seldom and reluctantly, except in situations where it is urgently needed advice.

1873 elected rector of the University of Berlin.

1881: elected to the Royal Society of London.

1883 after the suicide of her husband Kovalevskaya left without funds with five year old daughter, arrives in Berlin and stops at the Weierstrass. At the cost of great effort, using all his authority and communication, Weierstrass manage to procure her the position of professor at Stockholm University.

Tomb Weierstrass in Berlin

1885: 70th anniversary of the famous mathematician celebrated on a European scale.

1889: Weierstrass became very ill.

1891 Sofia Kovalevskaya suddenly died. Shaken Weierstrass sends flowers to her grave and burns all the letters of the Kovalevskaya (letters from him and were preserved at the beginning of the XX century published). Status Veyreshtrassa markedly deteriorates, he rarely gets up, edits his collected works.

1897 after a long illness Weierstrass died of complications from the flu.

In his honor, he was named a crater on the Moon Weierstrass. Name Weierstrass is Mathematics Institute WIAS Berlin.