International Journal of Mathematics and Mathematical Sciences 
Volume 24 (2000), Issue 9, Pages 643-647
doi:10.1155/S0161171200004154

Some sufficient conditions for strongly starlikeness

Milutin Obradović1 and Shigeyoshi Owa2

 1Department of Mathematics, Faculty of Technology and Metallurgy, 4 Karnegijova Street, Belgrade 11000, Serbia
2Department of Mathematics, Kinki University, Osaka, Higashi-Osaka 577-8502, Japan
Received 22 November 1999

Abstract

We consider strongly starlikeness of order α of functions f(z)=z+an+1zn+1+⋯ which are analytic in the unit disc and satisfy the condition of the form |f′(z)(zf(z))1+μ−1|<λ, 0<μ<1,  0<λ<1.