Korean J. Math. Vol. 31 No. 2 (2023) pp.229-242
DOI: https://doi.org/10.11568/kjm.2023.31.2.229

Order, type and zeros of analytic and meromorphic functions of [p,q]−ϕ order in the unit disc

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Published: Jun 30, 2023
Keywords:
meromorphic function, Analytic function, Unit disc, [p,q]−ϕ order, [p,q]−ϕ type
Mathematics Subject Classification:
30D35, 30D15

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Pulak Sahoo
Department of Mathematics, Midnapore College (Autonomous), Midnapore, Pin: 721101, West Bengal, India
Nityagopal Biswas
Department of Mathematics, Chakdaha College, Chakdaha, Nadia, Pin: 741222, West Bengal, India.

Abstract

In this paper, we investigate the [p,q]−ϕ order and [p,q]−ϕ type of f1+f2, f1f2 and f1f2, where f1 and f2 are analytic or meromorphic functions with the same [p,q]−ϕ order and different [p,q]−ϕ type in the unit disc. Also, we study the [p,q]−ϕ order and [p,q]−ϕ type of different f and its derivative. At the end, we investigate the relationship between two different [p,q]−ϕ convergence exponents of f. We extend some earlier precedent well known results.



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