lim(1+4+7+…+(3n-2))/(7n^2-5n),

lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2) lim[(4+7+...+3n+1)/(n^2-n)]= lim(1/n+2/n+3/n+4/n+5/n+……+n/n)=lim(1/n)+lim(2/n)+……+lim(n/n)成立吗?（n趋近于无穷大）为什么不成立? lim(1+4+7+…+(3n-2))/(7n^2-5n), lim(n+3)(4-n)/(n-1)(3-2n) lim(n^3+n)/(n^4-3n^2+1) 求当n→∞,Lim(1+2+3+4+……+(n-1)+n)/n 计算下列极限：1）lim(n→∞) 1/n3 2）lim(n→∞)4n+1/3n-11）lim(n→∞) 1/n3 2）lim(n→∞)4n+1/3n-13) lim(n→∞) (1/3)n4)lim(n→∞)n3+2n-5/5n3-n 5) lim(n→∞)(1+1/2n)n 6) lim(n→∞)2x3-x2+1/3x2+2x-9 7) lim(x→0 )sin3x/sin7x8) 求lim[1-2+3-4……+(2n-1)-2n]/2n-1 lim(x→∞）1+2+3+…+n/(n+2)(n+4)=? lim 1+4+7+...+(3n-2)/n(n+1)=______ lim√[(3n^2)+1]/(7n+1)=? 求极限lim(1/2n+3/4n+……+(2^n-1)/(2^n*n)) lim n趋向无穷大3n^3+n^2-3/4n^3+2n+1 1、lim n->无穷 根号[(n^4+n+1)-n^2]*(3n+4) 求lim(n+1)(n+2)(n+3)/(n^4+n^2+1) 一道极限题,lim[n^2(2n+1)]/(n^3+n+4)n->∞ lim[(n+3)/(n+1))]^(n-2) 【n无穷大】