Mathematician:John Wallis

Mathematician
English mathematician who made considerable contributions towards the invention of the calculus.

Credited with introducing the symbol $\infty$ for infinity.

One of the first English mathematicians to use the techniques of analytic geometry as defined by. Rediscovered a neat proof of Pythagoras' Theorem originally published by in the $12$th century.

Introduced negative and fractional exponents.

Nationality
English

History

 * Born: November 23, 1616, Ashford, Kent, England
 * 1649: Savilian Professor of Geometry at Oxford
 * Died: October 28, 1703, Oxford, Oxfordshire, England

Theorems and Definitions

 * Wallis's Product
 * Wallis's Number

Publications

 * 1655: Tract on Conic Sections
 * 1656: Arithmetica infinitorum (in which Wallis's Product appears)
 * 1659: De Cycloide et de Corporibus inde Genitis (which incorporated 's work on the rectification of the semicubical parabola)
 * 1685: Treatise on Algebra

Treatise of Angular Sections (unpublished for forty years after it was written)

Restored some ancient Greek texts, for example:


 * 's Harmonics
 * 's On the magnitudes and distances of the sun and moon

Dispute with Hobbes
From $1655$ onwards he was involved in an intellectual dispute with, whence various publications with titles like:


 * Due Correction for Mr Hobbes, or School Discipline for not saying his Lessons Aright

Non-mathematical

 * 1653: Grammatica linguae Anglicanae
 * 1687: Institutio logicae

Notable Quotes

 * These Imaginary Quantities (as they are commonly called) arising from the Supposed Root of a Negative Square (when they happen) are reputed to imply that the Case proposed is Impossible.