atsing66
幼苗
共回答了25个问题采纳率:80% 举报
(1)F(-x)=-F(x)而F(-x)=log(1/2) ((1+ax)/(-x-1))要F(-x)=-F(x)即要:(1+ax)/(-x-1) *(1-ax)/(x-1)=1ax-1=x-1a=1或-1经检验,a=1不合题意,a只能为-1(2)F(x)=log(1/2)((x+1)/(x-1))=log(1/2)(1+2/(x-1))由于u=2/(x-1)在(1,+∞)上单减v=1+u在u∈R时单增y=log(1/2)(v)在v∈R时单减所以F(x)在(1,+∞)上单增
1年前
7