TY - JOUR T1 - On Growth of Polynomials with Restricted Zeros AU - Abdullah Mir , AU - G. N. Parrey , JO - Analysis in Theory and Applications VL - 2 SP - 181 EP - 188 PY - 2016 DA - 2016/04 SN - 32 DO - http://doi.org/10.4208/ata.2016.v32.n2.7 UR - https://global-sci.org/intro/article_detail/ata/4664.html KW - Polynomial, maximum modulus principle, zeros. AB -
Let $P(z)$ be a polynomial of degree $n$ which does not vanish in $|z|< k $, $k\geq 1$. It is known that for each $0\leq s< n$ and $1\leq R\leq k$, $$M\big(P^{(s)},R\big)\leq \Big(\frac{1}{R^{s}+k^{s}}\Big)\Big[\Big\{\frac{d^{(s)}}{dx^{(s)}}(1+x^{n})\Big\}_{x=1}\Big]\Big(\frac{R+k}{1+k}\Big)^{n}M(P,1).$$ In this paper, we obtain certain extensions and refinements of this inequality by involving binomial coefficients and some of the coefficients of the polynomial $P(z)$.