一个映射函数的有理逼近

On Approximation of a Mapping Function by ational Functions

设０∈Ｇ，Ｇ是有界单连通区域，г＝Ｇ∈Ｃ（２，α），０＜α＜１．ｗ＝（ｚ），（０）＝０，（０）＞０是将Ｇ保角映射到｜ｗ｜＜１内的一个映射函数。本文利用ｗ＝（ｚ）的极值性质得到了给定极点的有理函数序列对它的一致逼近阶的估计．

Let G be a bounded simply connected domain,0∈G,Г=G∈ C(2,α), 0<α<1.Set , be the conformal map of G onto |w|<1.In this paper,we obtain,by means of the extremal property of the estimation order of the uniform approximation to (z) by sequence of the rational functions with preassigned poles.