=lim(n→∞)e^ln[√(n²+1)/(n+1)]ⁿ
=lim(n→∞)e^nln[√(n²+1)/(n+1)]
=lim(n→∞)e^n[½ln(n²+1)]-ln(n+1)]
根据海涅定理,求数列极限可转化为求函数极限
∵lim(x→+∞)x[½ln(x²+1)]-ln(x+1)]
=lim(x→+∞)[½ln(x²+1)]-ln(x+1)]/(1/x) 0/0型
=lim(x→+∞)[x/(x²+1)]-1/(x+1)]/(-1/x²) 洛必达
=lim(x→+∞)[-x³/(x²+1)]+x²/(x+1)]
=lim(x→+∞)[-x³(x+1)+x²(x²+1)]/[(x²+1)(x+1)]
=(x→+∞)[-x³+x²]/[(x³+x²+x+1)]
=-1
∴原极限=1/e