منابع مشابه
On the maximum modulus of a polynomial and its derivatives
Let f (z) be an arbitrary entire function and M(f ,r) = max |z|=r | f (z)|. For a polynomial P(z) of degree n, having no zeros in |z| < k, k ≥ 1, Bidkham and Dewan (1992) proved max |z|=r |P (z)| ≤ (n(r + k) n−1 /(1 + k) n)max |z|=1 |P(z)| for 1 ≤ r ≤ k. In this paper, we generalize as well as improve upon the above inequality.
متن کاملCalculating the Maximum Modulus of a Polynomial Using Stečkin’s Lemma
An algorithm for the calculation of the maximum modulus of a complex polynomial on the unit disc is described and evaluated. The algorithm is based on a lemma of Stečkin.
متن کاملOn the Derivative and Maximum Modulus Ofa Polynomial
The above inequality, which is an immediate consequence of Bernstein’s inequality on the derivative of a trigonometric polynomial, is best possible with equality holding for the polynomial p(z)= λzn, λ being a complex number. If we restrict ourselves to the class of polynomials having no zeros in |z| < 1, then the above inequality can be sharpened. In fact Erdös conjectured and later Lax [7] pr...
متن کاملInequalities for the Maximum Modulus of the Derivative of a Polynomial
Let P (z) be a polynomial of degree n and M(P, t) = Max|z|=t |P (z)|. In this paper we shall estimate M(P ′ , ρ) in terms of M(P, r) where P (z) does not vanish in the disk |z| ≤ K, K ≥ 1, 0 ≤ r < ρ < K and obtain an interesting refinement of some result of Dewan and Malik. We shall also obtain an interesting generalization as well as a refinement of well-known result of P. Turan for polynomial...
متن کاملextensions of some polynomial inequalities to the polar derivative
توسیع تعدادی از نامساوی های چند جمله ای در مشتق قطبی
15 صفحه اولذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Computational Methods and Function Theory
سال: 2021
ISSN: 1617-9447,2195-3724
DOI: 10.1007/s40315-021-00368-7