lim(n→无穷)[1/(n^2+1)+2/(n^2+2)+.+2n/(n^2+n)]

求极限 lim(n->无穷)[(3n^2-2)/(3n^2+4)]^[n(n+1)] lim(n趋于无穷)[n(n+1)/2]/n方+3n的极限是多少? 求极限：lim(x→无穷)(2^n-7^n)/(2^n+7^n-1)=? lim(n→正无穷)【n+2/n+1】的3n次方 求极限,lim(1+n)(1+n^2)(1+n^4)-----(1+n^2n)=?（n趋于无穷） 求极限lim((n+1)/(n2+1)+(n+2)/(n2+2)+...+(n+n)/(n2+n)),n趋近无穷 求极限lim(1/n)*[(sin(pi/n)+sin(2pi/n)+.+sin(n*pi/n)] n->无穷 lim[(n+3)/(n+1))]^(n-2) 【n无穷大】 求极限 lim(n无穷)n【(根号（n^2+1)-根号（n^2-1)】 求极限：lim((2n∧2-3n+1)/n+1)×sin n趋于无穷 求极限:Lim(1+1/n-1/n^2)^n n趋向于正无穷 求极限 n趋向于无穷 lim（(根号下n^2+1)/(n+1)）^n