##### Chapter 2

^{1} Cauchy, Augustin Louis (1789–1857) great French analyst, applied mathematician and group theorist. After Euler, the most prolific mathematician in history.

Heworked onwave theory, elasticity and group theory, introduced modern rigour into calculus, founded the theory of functions of a complex variable, inaugurated modern era in differential equations with his existence theorems.

^{2} Riemann, Georg Friedrich Bernhard (1826–1866) Great innovative German mathematician who made fundamental contributions to geometry and the theory of analytic functions of a complex variable and also to number theory, potential theory, topology and mathematical physics. Riemannian geometry provides the foundation for modern relativity theory.