The Viscount Brouncker  

The 2nd Viscount Brouncker (16201684)


Born  1620 Castlelyons, Ireland 
Died  5 April 1684 (aged 64) Westminster, London, England 
Residence  England 
Fields  Mathematician 
Institutions  Saint Catherine's Hospital 
Alma mater  University of Oxford 
Doctoral advisor  John Wallis 
Known for  Brouncker's formula 
William Brouncker, 2nd Viscount Brouncker, FRS (1620 – 5 April 1684) was an English mathematician.
Brouncker obtained a DM at the University of Oxford in 1647. He was one of the founders and the second President of the Royal Society. In 1662, he became Chancellor to Queen Catherine, then chief of the Saint Catherine's Hospital. His mathematical work concerned in particular the calculations of the lengths of the parabola and cycloid, and the quadrature of the hyperbola, which requires approximation of the natural logarithm function by infinite series. He was the first European to solve what is now known as Pell's equation. He was the first in England to take interest in generalised continued fractions and, following the work of John Wallis, he provided development in the generalised continued fraction of pi.
This formula provides a development of π/4 in a generalized continued fraction:
The convergents are related to the Leibniz formula for pi: for instance
and
Because of its slow convergence Brouncker's formula is not useful for practical computations of π.
Peerage of Ireland  

Preceded by William Brouncker 
Viscount Brouncker 1645–1684 
Succeeded by Henry Brouncker 

