lim(n→oo)(1/2+1/2^2+……+1/2^n)

lim(n→oo)(1/2+1/2^2+……+1/2^n) lim 4n^2+2/3n^2+1 (n→oo) lim(2/2*3*4+2/3*4*5+...2/(n+1)(n+2)(n+3)) n→oo lim (1+1/2+1/4+…+1/2^n) / (1+1/3+1/9+…+1/3^n) (n→oo) 极限lim(n->oo) n[ln(2+1/n)-ln2] 怎样算?貌似要用导数的?. 请问如何证明lim(n→∞)[n/(n2+n)+n/(n2+2n)+…+n/(n2+nn)]=1, lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2) 求lim n→∞ (1+2/n)^n+3 lim[(n+3)/(n+1))]^(n-2) 【n无穷大】 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 若lim(1+2+…+n)/n^2, lim(n→oo)(3^n/n)^1/n的值是什么