9楼: Originally posted by hylpy at 2016-01-12 15:48:05
∵e^{x}=1+\frac{x}{1!}+\frac{x^2}{2!}+\frac{x^3}{3!}+........,
∴\lim\limits_{x\to\infty}\frac{x^2}{e^{x}}=0.