Adriaan van Roomen
Van Roomen studied at the Jesuit College in Cologne and medicine at the University of Leuven. He was also in 1585 in Rome by Christopher Clavius . 1586 to 1592 he was professor of mathematics and medicine in Leuven and later in Würzburg, where he was a mathematician at the cathedral chapter. He married Anna Steegh, a niece of Gottfried Steegh, the personal physician of the Prince Bishop Julius Real Mespelbrunn. He stood with Tycho Brahe and Johannes Kepler in conjunction. Latter he met in 1600 in Prague. Among his students in Würzburg include Henning Scheunemann and Willibrord van Roijen Snell. In 1604 he was ordained a priest and taught mathematics from 1610 in Poland.
From friendship with Ludolph van Ceulen his employment grew with the determination of Pi, which he determined in 1593 to 16 decimal places. He also dealt with trigonometry and criticized the accuracy of the 1596 posthumously published trigonometric tables of Rheticus. He also scored on Pappus results based on polygons with maximum surface area for a given perimeter ( Isoperimetrisches problem).
He wrote a commentary on the algebra of al- Khwarizmi, the only two known copies were destroyed but ( burning of the library of Louvain) and the Second World War in the First World War.
He is known by a competition with François Viète who helped the latter to gain international recognition. Van Roomen had in 1594 the leading European mathematicians found the solution of an equation 45o as a task. Since Van Roomen had not approached certain French mathematician, the Dutch ambassador to France made to the King Henry IV, the pointed remark that there is probably no outstanding mathematician in France. The turned to Viète, solved this problem and 22 others also posed problems right off the bat with his algebraic method ( Viète later wrote legi Ut, ut solvi how to read, so solved ). He also presented his hand, Van Roomen the problem to solve the Apollonian problem with compass and ruler - although Van Roomen found a solution with hyperbolas (published 1596), which was not but only with a compass and ruler.