CERTAIN RESULTS OF STARLIKE AND CONVEX FUNCTIONS IN SOME CONDITIONS
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Dosyalar
Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Vinca Inst Nuclear Sci
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
The theory of geometric functions was first introduced by Bernard Riemann in 1851. In 1916, with the concept of normalized function revealed by Bieberbach, univalent function concept has found application area. Assume f(z) = z + Sigma(infinity)(n >= 2) (a(n)z(n)) converges for all complex numbers z with vertical bar z vertical bar < 1, and f(z) is one-to-one on the set of such z. Convex and starlike functions f(z) and g(z) are discussed with the help of subordination. The f(z) and g(z) are analytic in unit disc and f(0)=0, f'(0)=1, and g(0)=0, g'(0) - 1 = 0. A single valued function f(z) is said to be univalent (or schlict or one-to-one) in domain D subset of C never gets the same value twice; that is, if f(z(1)) - f(z(2)) not equal 0 for all z(1) and z(2) with z(1) not equal z(2). Let A be the class of analytic functions in the unit disk U ={z : vertical bar z vertical bar <1} that are normalized with f(0)=0, f'( 0)=1. In this paper we give the some necessary conditions for f (z) is an element of S*[a, a(2)] and 0 <= a(2) <= a <= 1 f'(z)(2(r) -1)[1 - f'(z)] + zf ''(z)/2(r) [f'(z)](2) This condition means that convexity and starlikeness of the function f of order 2(-r).
Açıklama
Anahtar Kelimeler
Analytic; Convex; Starlike; Unit Disk
Kaynak
Thermal Science
WoS Q Değeri
Q4
Scopus Q Değeri
Cilt
26
