函數y=(tan-1)/(tanx+1)的值域為

函數y=(tan-1)/(tanx+1)的值域為

令tanx=t(t∈R)
y=(t-1)/(t+1)=(t+1-2)/(t+1)=1-[2/(t+1)]≠1
故值域為{y|y≠1}