恐龙快打无双加强版:26=13*(1+0.008)n [n是(1+0.008)的N次方]着题怎么解哦 最好有详细步骤

"1^n+2^n+3^n......+m^n=? 1^n+2^n+3^n......+m^n= x=n*(n+1)*(n+2)*(n+3)....... n/(n-2)+n/(n-3)+n/(n-4)+n/(n-5)+...+2/(-1)=? 26=13*(1+0.008)n [n是(1+0.008)的N次方]着题怎么解哦 最好有详细步骤 lim（n→∞）[1/（n^2+n+1）+2/(n^2+n+2)+.....+n/(n^2+n+n)]=? (n+2)^2-n^2=4*(n+1) 证明C（0，n)^2+C(1,n)^2+……+C(n,n)^2=C(n,2n) 求证:N/3^N<3/N-1 (N属于N ,N>=3) Un=(1+1/n)^n