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http://dx.doi.org/10.22771/nfaa.2021.26.04.12

Lr INEQUALITIES OF GENERALIZED TURÁN-TYPE INEQUALITIES OF POLYNOMIALS  

Singh, Thangjam Birkramjit (Department of Mathematics, National Institute of Technology Manipur)
Krishnadas, Kshetrimayum (Department of Mathematics, National Institute of Technology Manipur)
Chanam, Barchand (Department of Mathematics, National Institute of Technology Manipur)
Publication Information
Nonlinear Functional Analysis and Applications / v.26, no.4, 2021 , pp. 855-868 More about this Journal
Abstract
If p(z) is a polynomial of degree n having all its zeros in |z| ≤ k, k ≤ 1, then for 𝜌R ≥ k2 and 𝜌 ≤ R, Aziz and Zargar [4] proved that $${\max_{{\mid}z{\mid}=1}}{\mid}p^{\prime}(z){\mid}{\geq}n{\frac{(R+k)^{n-1}}{({\rho}+k)^n}}\{{\max_{{\mid}z{\mid}=1}}{\mid}p(z){\mid}+{\min_{{\mid}z{\mid}=k}}{\mid}p(z){\mid}\}$$. We prove a generalized Lr extension of the above result for a more general class of polynomials $p(z)=a_nz^n+\sum\limits_{{\nu}={\mu}}^{n}a_n-_{\nu}z^{n-\nu}$, $1{\leq}{\mu}{\leq}n$. We also obtain another Lr analogue of a result for the above general class of polynomials proved by Chanam and Dewan [6].
Keywords
Polynomial; derivative; $L^r$ inequality;
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