Limits: Journal of Mathematics and Its Applications
Vol. 3 No. 1 (2006): Limits: Journal of Mathematics and Its Applications Volume 3 Nomor 1 Edisi Mei

On Subclass of Bazilevic Function B1(®), It's Distortion and the Fekete-Szego Problem

Marjono (Dept. of Mathematics, Brawijaya University)



Article Info

Publish Date
15 May 2006

Abstract

In this paper we present the distortion and the Fekete-SzegÄo problem of subclass of Bazilevi·c functions, B1(®). First, we present the result of Singh concerning the sharp value of the coe±cients for B1(®), ja2j, ja3j and ja4j. Second, we give a solution of the Fekete-SzegÄo problem, i.e. an estimate of ja3 ¡ ¹a 2 2j for any real and complex numbers ¹ where a2 and a3 are the coe±cients of functions f in B1(®), where B1(®) is defined by (2), i.e. for each ® > 0 and for z 2 D, Re f 0 (z) f(z) z ®¡1 > 0. These results are sharp for the functions f0 defined by (3) for any real number ¹ which satisfies ¹ < (1 ¡ ®)=2, or ¹ ¸ (4 + 3® + ® )=[2(2 + ®)] and for any complex number ¹ which satisfies j3 + ® ¡ 2¹(2 + ®)j ¸ (1 + ®) 2 . These results are sharp for the functions f1 defined by (4) for the other real and complex numbers ¹. Next, we use similar methods to get estimates for linear expressions involving higher coefficients of function in B1(®).

Copyrights © 2006






Journal Info

Abbrev

limits

Publisher

Subject

Computer Science & IT Mathematics

Description

Limits: Journal of Mathematics and Its Applications merupakan jurnal yang diterbitkan oleh Pusat Publikasi Ilmiah LPPM Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia. Limits menerima makalah hasil riset di semua bidang Matematika, terutama bidang Analisis, Aljabar, Pemodelan Matematika, ...