极限 1/2+3/2^2+5/2^3＋……+（2n-1）/2^n

求极限Xn=n/(n^2+1)+n/(n^2+2)+n/(n^2+3)+……+n/(n^2+n), 1/(n+1)+1/(n+2)+1/(n+3)+ ……+1/3n 极限 求极限lim(x→∞)（1/n+2/n+3/n..+n/n） ∑（N等于1,2,3,4..n） 5^N/N!,极限怎么求 求极限 lim【1/（n^2+n+1）+2/（n^2+n+2）+3/（n^2+n+3）+……+n 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 极限计算：lim { [1+3+5+…+(2n+1)] / (n^2) }^(n)=( 求极限lim(1/2n+3/4n+……+(2^n-1)/(2^n*n)) lim(n→∞) （n+1）(n+2) (n+3)/5n3次方+n 的极限? 用夹逼准则和重要极限两种方法计算极限lim(2^n+3^n+4^n+5^n+6^n)^(1/n)n趋近于... 求极限 lim(n->无穷)[(3n^2-2)/(3n^2+4)]^[n(n+1)] 求极限lim [ 2^(n+1)+3^(n+1)]/2^n+3^n (n→∞)