f(z)=1/(z+1) - 1/(z+2)为了在z=a点展开,我们做如下变形：=1/[(a+1)-(a-z)] - 1/[(a+2)-(a-z)]=[1/(a+1)]*{1/[1-(a-z)/(a+1)]} - [1/(a+2)]*{1/[1-(a-z)/(a+2)]} 这样就可以看成是两个等比级数的和了,公比分别是(a-z...