410 research outputs found

    Integral mean estimates for the polar derivative of a polynomial

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    Let P(z) P(z) be a polynomial of degree n n having all zeros in ∣z∣≤k|z|\leq k where k≤1,k\leq 1, then it was proved by Dewan \textit{et al} that for every real or complex number α\alpha with ∣α∣≥k|\alpha|\geq k and each r≥0r\geq 0 n(∣α∣−k){∫02π∣P(eiθ)∣rdθ}1r≤{∫02π∣1+keiθ∣rdθ}1rMax∣z∣=1∣DαP(z)∣. n(|\alpha|-k)\left\{\int\limits_{0}^{2\pi}\left|P\left(e^{i\theta}\right)\right|^r d\theta\right\}^{\frac{1}{r}}\leq\left\{\int\limits_{0}^{2\pi}\left|1+ke^{i\theta}\right|^r d\theta\right\}^{\frac{1}{r}}\underset{|z|=1}{Max}|D_\alpha P(z)|. \indent In this paper, we shall present a refinement and generalization of above result and also extend it to the class of polynomials P(z)=anzn+∑ν=μnan−νzn−ν,P(z)=a_nz^n+\sum_{\nu=\mu}^{n}a_{n-\nu}z^{n-\nu}, 1≤μ≤n,1\leq\mu\leq n, having all its zeros in ∣z∣≤k|z|\leq k where k≤1k\leq 1 and thereby obtain certain generalizations of above and many other known results.Comment: 8 page

    New Generalizations of Exponential Distribution with Applications

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    The main purpose of this paper is to present k-Generalized Exponential Distribution which among other things includes Generalized Exponential and Weibull Distributions as special cases. Besides, we also obtain three-parameter extension of Generalized Exponential Distribution. We shall also discuss moment generating functions (MGFs) of these newly introduced distributions

    Lp mean estimates for an operator preserving inequalities between polynomials

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    If P(z)P(z) be a polynomial of degree at most nn which does not vanish in ∣z∣<1|z| < 1, it was recently formulated by Shah and Liman \cite[\textit{Integral estimates for the family of BB-operators, Operators and Matrices,} \textbf{5}(2011), 79 - 87]{wl} that for every R≥1R\geq 1, p≥1p\geq 1, ∥B[P∘σ](z)∥p≤Rn∣Λn∣+∣λ0∣∥1+z∥p∥P(z)∥p,\left\|B[P\circ\sigma](z)\right\|_p \leq\frac{R^{n}|\Lambda_n|+|\lambda_{0}|}{\left\|1+z\right\|_p}\left\|P(z)\right\|_p, where BB is a Bn \mathcal{B}_{n}-operator with parameters λ0,λ1,λ2\lambda_{0}, \lambda_{1}, \lambda_{2} in the sense of Rahman \cite{qir}, σ(z)=Rz\sigma(z)=Rz and Λn=λ0+λ1n22+λ2n3(n−1)8\Lambda_n=\lambda_{0}+\lambda_{1}\frac{n^{2}}{2} +\lambda_{2}\frac{n^{3}(n-1)}{8}. Unfortunately the proof of this result is not correct. In this paper, we present a more general sharp LpL_p-inequalities for Bn\mathcal{B}_{n}-operators which not only provide a correct proof of the above inequality as a special case but also extend them for 0≤p<1 0 \leq p <1 as well.Comment: 16 Page
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