This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f(x) ∈ L^*M[0, 1], changes its sign at most once in (0, 1), then there exists ...This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f(x) ∈ L^*M[0, 1], changes its sign at most once in (0, 1), then there exists x0 ∈ (0, 1) and a polynomial Pn∈ Fin(+) such that ||f(x)-x-x0/Pn(x)||M≤Cω(f,n-1/2)M, where Пn(+) indicates the set of all polynomials of degree n with positive coefficients展开更多
基金Supported by Inner Mongolia Natural Science Foundations of China (200408020108).
文摘This paper discusses the approximation by reciprocals of polynomials with positive coefficients in Orlicz spaces and proved that if f(x) ∈ L^*M[0, 1], changes its sign at most once in (0, 1), then there exists x0 ∈ (0, 1) and a polynomial Pn∈ Fin(+) such that ||f(x)-x-x0/Pn(x)||M≤Cω(f,n-1/2)M, where Пn(+) indicates the set of all polynomials of degree n with positive coefficients