lim(x→+∞)f(x)=lim(x→+∞)[(1+x)/√(1+x^2)]=lim(x→+∞)[(1/x+1)/√(1/x^2)+1]=1渐近线 y=1lim(x→-∞)f(x)=lim(x→-∞)[(1+x)/√(1+x^2)]=-1渐近线 y=-1
