求函数极限 lim x(ln(x+1)-lnx){x->+∞}

问题描述:

求函数极限 lim x(ln(x+1)-lnx){x->+∞}

limx(ln(x+1)/x)=lim (ln(x+1)/x)^x=lne=1

=lim x(ln(x+1)/x) {x->+∞}
=lim x(ln(1+1/x)) {x->+∞}
=lim x*1/x (洛必达法则)
=1

lim x(ln(x+1)/x)
=lim ln[(x+1)/x]^x
=ln lim(1+1/x)^x
=ln e
=1