Vaclav Jerabek

Born: 11 December 1845 in Kolodeje, Pardubice, Czech Republic
Died: 20 December 1931 in Telc, Czech Republic

Vaclav Jerabek obtained high school education at a lower Realschule in Pardubice, and then at a higher Realschule in Pisek. From 1866 to 1870 he studied at the Vienna Polytechnic. Having obtained the necessary qualifications in Vienna, he became a high school teacher. He began his teaching career at a higher general Realschule in Litomysl in 1870, where he attained full professorship in 1872. In 1873 he moved to a higher Realschule in Telc.

The historic town of Telec dates back to 1100. The website of the town states:-

The second half of the 19th century brings a reinforcement of national political maturity. An important role was played by the schools founded in Telc in 1852. Thanks to the teachers and professors as well as to all the others who were operating there ... there rose a few associations ... and Telc played an important role within the whole region of Southwest Moravia.
In 1881 Jerabek was appointed professor at a newly founded Czech Realschule in Brno. In 1901 he became the director of the school, and he continued in that position until 1907 when he retired. In his later years he suffered from a cataract, which progressively made him almost completely blind despite surgery.

Jerabek was a member of the Royal Bohemian Society of Sciences, the Moravian Society of Natural Sciences, and a honorary member of the Union of Czech Mathematicians.

His main research interest was in constructive geometry. He is best remembered by mathematicians for the Jerabek hyperbola. Given a triangle, the isogonal-conjugate images of lines are conics passing through the vertices of the triangle. The Jerabek hyperbola is the isogonal-conjugate image of the Euler line. It is a rectangular hyperbola, passing through the orthocenter and the circumcenter and many other interesting points of the triangle. The centre of the Jerabek hyperbola lies on the nine-point circle.

Jerabek wrote over 50 papers, published mostly in Casopis pro pestovani matematiky a fysiky, some of them in the Belgian journal Mathesis. He donated his extensive library to the University of Brno.

Article by: Based on reference [1], translated by Emil Jerabek, communicated by Francisco Javier García Capitán.

July 2007
MacTutor History of Mathematics