来源:学生作业帮 编辑:百度作业网作业帮 分类:数学作业 时间:2024/06/24 05:10:52
求极限,麻烦各位写清楚拍过来,
![](http://img.wesiedu.com/upload/8/3f/83fe1d6afd30059ab101cc7e9aa916e8.jpg)
lim xsin(1/x)
=lim sin(1/x)/(1/x) 设 t = 1/x.当 x→∞时,t → 0
=lim sint/t
=1
lim√(1-cosx)/|x|
=lim|√2*sin(x/2)|/|x| 注:1-cosx = 2[sin(x/2)]^2
=2√2*lim|sin(x/2)/(x/2)|
=2√2*| lim sin(x/2)/(x/2) |
=2√2 * 1
=2√2
再问: 哇,好感动。。。。