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