求1-1/2+1/3-1/4+1/5-1/6+.+1/(2n-1)-1/2n=?n→∞

证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n Sn=n(n+2)(n+4)的分项等于1/6[n(n+2)(n+4)(n+5)-(n-1)n(n+2)(n+4)]吗? 求极限lim [ 2^(n+1)+3^(n+1)]/2^n+3^n (n→∞) lim n →∞ (1^n+3^n+2^n)^1/n,求数列极限 求极限 lim(n→∞)[根号(n^2+4n+5)-(n-1)] = 求极限lim(x→∞)（1/n+2/n+3/n..+n/n） 2^n/n*(n+1) 求lim n→∞ (1+2/n)^n+3 [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 1\n(n+3)+1\(n+3)(n+6)+1\(n+6)(n+9)=1\2 n+18 n为正整数,求n的值 证明(1+2/n)^n>5-2/n（n属于N+,n>=3) lim（n→∞) （(2n!/n!*n)^1/n的极限用定积分求