limx→1(1/lnx-1/x-1) 等于多少

问题描述:

limx→1(1/lnx-1/x-1) 等于多少

lim(x→1) [1/lnx-1/(x-1)]
=lim(x→1) [x-1-lnx]/[lnx(x-1)](这是0/0型,运用洛必达)
=lim(x→1)(1-1/x)/[(x-1)/x+lnx]
=lim(x→1)(x-1)/(x-1+xlnx)(再运用洛必达法则)
=lim(x→1)1/(1+lnx+1)
=1/2
有用的话,给个好评吧O(∩_∩)O~~