1/1*2+1/2*3…+1/n(n+1)等于多少?

证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 2^n/n*(n+1) [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 化简n分之n-1+n分之n-2+n分之n-3+.+n分之1 化简n分之n-1+n分之n-2+n分之n-3+.+n分之1 化简(n+1)(n+2)(n+3) 当n为正偶数,求证n/(n-1)+n(n-2)/(n-1)(n-3)+...+n(n-2).2/(n-1)(n-3)...1=n (1/(n^2 n 1 ) 2/(n^2 n 2) 3/(n^2 n 3) ……n/(n^2 n n)) 当N越于无穷大的极限(1/(n^2+n+1 ) +2/(n^2+n+2) +3/(n^2+n+3) ……n/(n^2+n+n)) 当N越于无穷大的极限 1+(n+2)+(2n+3)+(3n+4)+(4n+5)+……((n-1)n+n)的答案 {[(1+n)(2+n)(3+n)……(n+n)]^(1/n)}/n当趋向正无穷 求其极限 e^(1/n)+e^(2/n)+e^(3/n)+…+e^(n-1/n)+e^(n/n)=? (n+2)!/(n+1)! lim2^n +3^n/2^n+1+3^n+1 n(n+1)(n+2)(n+3)+1 因式分解 n(n+1)(n+2)(n+3)+1等于多少 3(n-1)(n+3)-2(n-5)(n-2) lim(n+3)(4-n)/(n-1)(3-2n)