求数学高手帮忙解题啊 求极限 lim n[1/(n^2+1)+1/(n^2+2^2）+……+1/(n^n+n^n)] (n趋向于无穷大，n^n表示n
1个回答
展开全部
=lim n^2·[1/(n^2+1)+1/(n^2+2^2）+……+1/(n^n+n^n)] /n
=lim [n^2/(n^2+1)+n^2/(n^2+2^2）+……+n^2/(n^n+n^n)]·(1/n)
=lim [1/(1+(1/n)^2) +1/(1+(2/n)^2) +……+ 1/(1+(n/n)^2))]·(1/n)
=∫《x从0到1》1/(1+x²) dx
=arctanx |《x从0到1》
=arctan1 - arctan0
=π/4
=lim [n^2/(n^2+1)+n^2/(n^2+2^2）+……+n^2/(n^n+n^n)]·(1/n)
=lim [1/(1+(1/n)^2) +1/(1+(2/n)^2) +……+ 1/(1+(n/n)^2))]·(1/n)
=∫《x从0到1》1/(1+x²) dx
=arctanx |《x从0到1》
=arctan1 - arctan0
=π/4
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
