求大佬,用夹逼定理求数列极限。

Xn=n/2n^2+1+n/2n^2+2…+n/2n^2+n一般方法最好多加几个例题,谢谢!
2024-12-27 02:48:11
推荐回答(1个)
回答1:

n/(2n^2+1)+ n/(2n^2+2)+...+n/(2n^2+n)
n^2/(2n^2+n) ≤n/(2n^2)+1+ n/(2n^2+2)+...+n/(2n^2+n)≤ n^2/(2n^2+1)
lim(n->∞) n^2/(2n^2+n) =lim(n->∞) n^2/(2n^2+1) =1/2
=>
lim(n->∞) [n/(2n^2+1)+ n/(2n^2+2)+...+n/(2n^2+n)] =1/2