黑道风云第二部有杨威:极限问题10

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/05 13:38:46
n趋于无穷时,lim(1/(n^2)+2/(n^2)+…+n/(n^2))=?
答案1/2

lim(1/(n^2)+2/(n^2)+…+n/(n^2))
=lim((1+2+3+...+n)/(n^2))
=lim((1+n)*n/(2n^2))
=lim((n^2+n)/(2n^2))
比较最高次项的系数,得lim(1/(n^2)+2/(n^2)+…+n/(n^2))=1/2