- Research Article
- 10.28919/10.28919/jmcs/5576
On maximum modulus of polar derivative of a polynomial
- May 04, 2021
- J. Math. Comput. Sci.
- Kshetrimayum Krishnadas + 1 more +1
Let p(z) be a polynomial of degree n and for any real or complex number α, Dα p(z) denotes the polar derivative of p(z) with respect to α, then D α p(z) = np(z) + (α −z)p’(z). In this paper, we consider the more general class of polynomials p(z) = a 0 + ∑ a ν z ν , 1 ≤ µ ≤ n, not vanishing in |z| 0, to estimate max |D α p(z)| in terms of max |p(z)| by involving some coefficients of p(z), where 0 < r ≤ ρ ≤ k. Interestingly, the results improve and extend other well known inequalities to polar derivative. Moreover, our results give several interesting results as special cases.
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