洛必达法则:
原式=(e^2x-e^x-x)/(xe^x-x) (省略lim)
(上下各求一次导)->(2e^2x-e^x-1)/(e^x+xe^x-1)
(上下各求一次导)->(4e^2x-e^x)/(2e^x+xe^x)
(将x=0)带入->3/2。
这道题也可以用泰勒展开:
原式=(e^2x-e^x-x)/(xe^x-x) (省略lim)
=[(1+2x+2x^2+o(x^2))-(1+x+x^2/2+o(x^2))-x]/[x(1+x+x^2/2+o(x^2))-x]
=(3x^2/2+o(x^2))/(x^2+o(x^2))
=3/2
追问能拿纸写吗?
这样我看不懂
多谢
追答![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/30adcbef76094b36a03c4d21a5cc7cd98c109d4b?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
或
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/9f2f070828381f3059c9dc65af014c086f06f02e?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
追问下面用了什么定理或法则?
追答泰勒多项式展开。