Let S<sup>*</sup> be the class of starlike functions in unit disc.For f∈S<sup>*</sup>,denote its radiusof convexity by r<sub>0</sub> and let d<sub>0</sub>=（?）|f（z）|...Let S<sup>*</sup> be the class of starlike functions in unit disc.For f∈S<sup>*</sup>,denote its radiusof convexity by r<sub>0</sub> and let d<sub>0</sub>=（?）|f（z）|,d<sup>*</sup>=inf{|β||f（z）≠β,|z|【1}.In this paper weprove d<sub>0</sub>/d<sup>*</sup>≥0.45,thus improving the result of d<sub>0</sub>/d<sup>*</sup>≥0.38 by McCarty,C.P.and Tepper,D.E.and d<sub>0</sub>/d<sup>*</sup>≥0.41 by Huang Xinzhong.展开更多
文摘Let S<sup>*</sup> be the class of starlike functions in unit disc.For f∈S<sup>*</sup>,denote its radiusof convexity by r<sub>0</sub> and let d<sub>0</sub>=（?）|f（z）|,d<sup>*</sup>=inf{|β||f（z）≠β,|z|【1}.In this paper weprove d<sub>0</sub>/d<sup>*</sup>≥0.45,thus improving the result of d<sub>0</sub>/d<sup>*</sup>≥0.38 by McCarty,C.P.and Tepper,D.E.and d<sub>0</sub>/d<sup>*</sup>≥0.41 by Huang Xinzhong.
