1+3+5+7+9+……+(2n-1)+(2n+1)+(2n+3)等于几?
1+3+7+9+…+(2n-1)+(2n+1)+(2n+3)等于几
1+3+5+7+9+……+(2n-1)+(2n+1)+(2n+3)等于几?
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^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
lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2)
1,2,4,7,11,16.n n等于几
n(n+1)(n+2)等于多少?
∑(N等于1,2,3,4..n) 5^N/N!,极限怎么求
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(1+2/n)^n>5-2/n(n属于N+,n>=3)
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
求极限Xn=n/(n^2+1)+n/(n^2+2)+n/(n^2+3)+……+n/(n^2+n),