• Title/Summary/Keyword: Taylor-Maclaurin coefficient

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Certain Subclasses of Bi-Starlike and Bi-Convex Functions of Complex Order

  • MAGESH, NANJUNDAN;BALAJI, VITTALRAO KUPPARAOo
    • Kyungpook Mathematical Journal
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    • v.55 no.3
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    • pp.705-714
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    • 2015
  • In this paper, we introduce and investigate an interesting subclass $M_{\Sigma}({\gamma},{\lambda},{\delta},{\varphi})$ of analytic and bi-univalent functions of complex order in the open unit disk ${\mathbb{U}}$. For functions belonging to the class $M_{\Sigma}({\gamma},{\lambda},{\delta},{\varphi})$ we investigate the coefficient estimates on the first two Taylor-Maclaurin coefficients ${\mid}{\alpha}_2{\mid}$ and ${\mid}{\alpha}_3{\mid}$. The results presented in this paper would generalize and improve some recent works of [1],[5],[9].

CERTAIN NEW FAMILIES FOR BI-UNIVALENT FUNCTIONS DEFINED BY A KNOWN OPERATOR

  • Wanas, Abbas Kareem;Choi, Junesang
    • East Asian mathematical journal
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    • v.37 no.3
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    • pp.319-331
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    • 2021
  • In this paper, we aim to introduce two new families of analytic and bi-univalent functions associated with the Attiya's operator, which is defined by the Hadamard product of a generalized Mittag-Leffler function and analytic functions on the open unit disk. Then we estimate the second and third coefficients of the Taylor-Maclaurin series expansions of functions belonging to these families. Also, we investigate Fekete-Szegö problem for these families. Some relevant connections of certain special cases of the main results with those in several earlier works are also pointed out. Two naturally-arisen problems are given for further investigation.

BI-UNIVALENT FUNCTIONS CONNECTED WITH THE MITTAG-LEFFLER-TYPE BOREL DISTRIBUTION BASED UPON THE LEGENDRE POLYNOMIALS

  • El-Deeb, Sheza M.;Murugusundaramoorthy, Gangadharan;Alburaikan, Alhanouf
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.2
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    • pp.331-347
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    • 2022
  • In this paper, we introduce new subclasses of analytic and bi-univalent functions associated with the Mittag-Leffler-type Borel distribution by using the Legendre polynomials. Furthermore, we find estimates on the first two Taylor-Maclaurin coefficients |a2| and |a3| for functions in these subclasses and obtain Fekete-Szegő problem for these subclasses. We also state certain new subclasses of Σ and initial coefficient estimates and Fekete-Szegő inequalities.