,1.x→0时,x/(x-1)趋于0,lim(x→0)f(x)=lim(x→0)1/(1-2^(x/(x-1))=∞2.x→1+时,x/(x-1)趋于+∞,lim(x→1+)f(x)=lim(x→1+)1/(1-2^(x/(x-1))=0x→1-时,x/(x-1)趋于-∞,2^(x/(x-1))趋于0lim(x→1-)f(x)=lim(x→1-)1/(1-2^(x/(x-1))=1所以:lim(x→1)f(x)不存在