求极限~limx→∞ ln x+5/√x^2+1

问题描述:

求极限~limx→∞ ln x+5/√x^2+1
RT~

limx→∞ ln (x+5)/√(x^2+1)(这是∞/∞型,运用洛必达法则得)
=limx→∞ 1/[(x+5)*2x/2√(x^2+1)]
=limx→∞ √(x^2+1)/[(x+5)*x]=0啊~题目是这样的~求解答~limx→∞ ln (x+5/√x^2+1)limx→∞ ln (x+5/√x^2+1)=limx→∞ ln √[(x^2+10x+25)/(x^2+1)]=limx→∞ 1/2ln[(x^2+10x+25)/(x^2+1)]=limx→∞ 1/2ln[1+(10x+24)/(x^2+1)]=limx→∞ 1/2ln(1+0)=0