|(z-1)/(z+1)|>a(a>0)它的区域怎么求

Question

|(z-1)/(z+1)|>a(a>0)它的区域怎么求

Answer 1

|(Z+1-2)/(Z+1)|/＞a
|1-2/(Z+1)|＞a
因为a>0
所以1-2/(z+1)≠0
Z≠1
Z的区域负无穷到1,1到正无穷是开区间