English

Partial sums of the normalized Dini functions

Complex Variables 2016-06-21 v1

Abstract

Let (wα,v)m(z)=z+n=1manzn+1\left( w_{\alpha ,v}\right) _{m}(z)=z+\sum\limits_{n=1}^{m}a_{n}z^{n+1} be the sequence of partial sums of normalized Dini functions wα,v(z)=z+n=1anzn+1w_{\alpha ,v}(z)=z+\sum\limits_{n=1}^{\infty }a_{n}z^{n+1} where a_{n}=\frac{\left( -1\right) ^{n}\left( 2n+\alpha \right) }{\alpha 4^{n}n!\left( v+1\right) _{n}% }. The aim of the present paper is to obtain lower bounds for R{wα,v(z)(wα,v)m(z)},\mathcal{R} \left\{ \frac{w_{\alpha ,v}(z)}{\left( w_{\alpha ,v}\right) _{m}(z)}\right\} , R{(wα,v)m(z)wα,v(z)},\mathcal{R}\left\{ \frac{\left( w_{\alpha ,v}\right) _{m}(z)}{w_{\alpha ,v}(z)}\right\} , R{wα,v(z)(wα,v)m(z)}\mathcal{R}\left\{ \frac{w_{\alpha ,v}^{^{\prime }}(z)}{ \left( w_{\alpha ,v}\right) _{m}^{^{\prime }}(z)}\right\} and R{(wα,v)m(z)wα,v(z)}\mathcal{R} \left\{ \frac{\left( w_{\alpha ,v}\right) _{m}^{^{\prime }}(z)}{w_{\alpha ,v}^{^{\prime }}(z)}\right\} . Also we give a few geometric description regarding image domains of some functions.

Keywords

Cite

@article{arxiv.1606.05906,
  title  = {Partial sums of the normalized Dini functions},
  author = {Halit Orhan and İbrahim Aktaş},
  journal= {arXiv preprint arXiv:1606.05906},
  year   = {2016}
}
R2 v1 2026-06-22T14:28:50.501Z