On the Fekete-Szeg6 problem for close-to-convex functions II

نویسنده

  • WOLFRAM KOEPF
چکیده

Let C (fl), fl > 0, denote the family of no rmal i zed c loseto-convex funct ions of o rder ft. F o r fl = 1 this is the usual set of c loseto-convex functions, which had been defined by Kap lan . In a prev ious pape r [3] we solved the Fekete-Szeg6 p r o b l e m of maximiz ing l a 3 2 a2l, 2 ~ [0, 1], for c loseto-convex functions. The largest n u m b e r 20 for which [a a 20 a2[ is max imized by the K o e b e funct ion z / ( 1 z) 2 is 20 = 1/3. N o w we generalize this result to C (fl), fl > 1, showing tha t the largest n u m b e r 20 (fl) for which l a 3 20 (fl)a2[ is max imized over C (fl) by k a with

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تاریخ انتشار 2005