https://blog.csdn.net/ccnt_2012/article/details/81114920
如何证明(1+1/x)^x的极限是e
令1/x=t,t趋向0,原极限=S=(1+t)^(1/t)
则lnS=[ln(1+t)]/t=(罗比达法则,分子分母都求导)=[1/(1+t)]/1,0代入得lnS趋向1,故S趋向e.
https://blog.csdn.net/saltriver/article/details/52718072
https://blog.csdn.net/saltriver/article/details/53982885