当X趋向于1时,函数((x^2-1)/(x-1))e^1/(x-1)的左右极限怎么求啊

问题描述:

当X趋向于1时,函数((x^2-1)/(x-1))e^1/(x-1)的左右极限怎么求啊

。。行人更在春山外。。 欧阳修 踏莎行

令 x-1=t,t-->0
lim (x-->+1)((x^2-1)/(x-1))e^1/(x-1)
=(x-->+1)((x+1)e^1/(x-1)
=lim (t-->+0)(t+2)e^1/t
=+∞
lim (x-->1-)((x^2-1)/(x-1))e^1/(x-1)
=(x-->1-)((x+1)e^1/(x-1)
=lim (t-->-0)(t+2)e^1/t
=0