Bernstein's theorem (approximation theory)

Bernstein's theorem in the context of approximation theory, particularly in the field of polynomial approximation, refers to the result that relates to the uniform approximation of continuous functions on a closed interval using polynomial functions. The theorem states that if \( f \) is a continuous function defined on the interval \([a, b]\), then \( f \) can be uniformly approximated as closely as desired by a sequence of polynomials.