1+3+5+7+9+……+(2n-1)
lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2)
(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
1+3+7+9+…+(2n-1)+(2n+1)+(2n+3)等于几
已知Sn=2+5n+8n^2+…+(3n-1)n^n-1(n∈N*)求Sn
用数学归纳法证明“(n+1)(n+2)…(n+n)=2^n·1·3·5…(2n-1)(n∈N*)”时,从n=k到n=k+
证明1/(n+1)+1/(n+2)+1/(n+3)+……+1/(n+n)
求极限Xn=n/(n^2+1)+n/(n^2+2)+n/(n^2+3)+……+n/(n^2+n),
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
1+3+5+7+9+……+(2n-1)+(2n+1)+(2n+3)等于几?
VB编程n!+(n+1)!+(n+2)!+(n+3)!+……+(n+m)!
计算:C(1,n)+2C(2,n)+3C(3,n) + … + nC(n,n)
1+3+5+7+9+…+(2n-1)+(2n+1)+(2n+3)