[(√n^2-1)+(√n^2-4)+(√n^2-9)+……(√n^2-(n-1)^2)]/n^2

2^n/n*(n+1) 证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n [(√n^2-1)+(√n^2-4)+(√n^2-9)+……(√n^2-(n-1)^2)]/n^2 limn→∞n√(1+1/n)(1+2/n)...(1+n/n)等于多少? (1/(n^2 n 1 ) 2/(n^2 n 2) 3/(n^2 n 3) ……n/(n^2 n n)) 当N越于无穷大 判断1/√(n^2+n) 敛散性 正项级数(n-√n)/(2n-1)还有1/√n*ln(n+1/n-1)还有√(2n-1/3n+2)的敛散性 用数学归纳法证明：1×2×3+2×3×4+…+n×(n+1)×(n+2)＝n(n+1)(n+2)(n+3)4(n∈N lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2) 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 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? 证明不等式：(1/n)的n次方+(2/n)的n次方+……+(n/n)的n次方