The famous mathematicians,their life and contribution in the field of mathematics.PLZ help.

The list of famous mathematicians is a long one. You can at least a dozen names here:
http://www.mathematicianspictures.com/Shirts.htm#Themathematicians

Pick some you are interested in and use an internet search engine such as Google for biographical information. The Wikipedia articles are usually very good. Here is an example:

http://en.wikipedia.org/wiki/Ren%C3%A9_Descartes

René Descartes, a French mathematician and philosopher, is famous for his contributions to both mathematics and philosophy. One of his most notable achievements is the development of Cartesian coordinates, which laid the foundation for analytic geometry. This system of coordinates allows geometric figures to be described using algebraic equations, connecting the fields of algebra and geometry. Descartes also made significant contributions to the development of calculus and pioneered the field of analytical geometry. In philosophy, he is best known for his statement "Cogito, ergo sum" ("I think, therefore I am"), which is central to his theory of knowledge. Descartes' works had a profound impact on the fields of mathematics, philosophy, and science, establishing him as one of the most influential thinkers in history.