Weierstraßs

Weierstraß is a surname. It is most famously associated with Karl Weierstrass, a German mathematician. Weierstrass (1815-1897) is considered one of the founders of modern analysis. He made significant contributions to the rigorous formulation of calculus, including the epsilon-delta definition of limits and the formalization of continuity, differentiability, and convergence. His work on the Weierstrass approximation theorem established that continuous functions on a closed interval can be uniformly approximated by polynomials. This was a crucial step in the development of functional analysis. Beyond analysis, Weierstrass also worked on elliptic functions and the theory of surfaces. His emphasis on rigor profoundly influenced the direction of mathematics in the late 19th and early 20th centuries. The term "Weierstraß" itself can also refer to mathematical concepts or objects named after him, such as the Weierstraß function, which is a continuous function that is nowhere differentiable.