一类单叶调和函数族的极值点与支撑点

Extreme pionts and support points of a class of harmonic univalent functions

设T是由具有形式f(z)=z-∑+∞n=2anzn-∑+∞n=2bnz-n,且满足条件an≥0,bn≥0,∑+∞n=2n(an+bn)≤1的所有复值调和函数组成的函数族.找出了函数族T的极值点与支撑点.

Let T=｛f(z)∶f(z)=z-∑+∞n=2a_nz^n-∑+∞n=2b_nz-~n,a_n≥0,b_n≥0,∑+∞n=2n(a_n+b_n)≤1｝. The extreme points and support points of T are obtained.