摘要
本文证明了,对任意正整数n,当函数W(z)在单位圆U:|z|<1内正则,W(0):0,且不等式在U内成立,则不等式在U内也成立。
Let n be a positive integer, and let W(z) be regular in the Unit disk U: |z| <1, with W(0) = 0. In this paper the author has proved that the differential inequality |W+zW+...+zW(n)<1, for z∈U, implies |W(z)|<1 for z∈U.
出处
《西南师范大学学报（自然科学版）》
CAS
CSCD
1989年第4期81-85,共5页
Journal of Southwest China Normal University(Natural Science Edition)
关键词
复平面
正则
柯西不等式
complex plane
regular
Cauchy inequality
