(-无穷,-1)并(1,+无穷)当x<=0时,f(x)=2^(-x)-1,为一减函数,求2^(-x)-1=1得x=-1,所以当x<-1时f(x)>1当x>0时,f(x)=x^(1/2),为一增函数,求x^(1/2)=1得x=1,所以当x>1时f(x)>1综上所述:当x在 (-无穷,-1)并(1,+无穷) 内时,可满足条件