lim(1/(x+1)+1/(x^2-1)) x->-1 求极限

题目

lim(1/(x+1)+1/(x^2-1)) x->-1 求极限

答案

原式=lim(x->-1) [(x-1+1)/(x+1)(x-1)]
=lim(x->-1) [x/(x+1)(x-1)]
因为
lim(x->-1) [(x+1)(x-1)/x]=0
所以
原式=∞.