化简:4n+3×4n-1+32×4n-2+…+3n-1×4+3n.
化简:1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)
化简:4n+3×4n-1+32×4n-2+…+3n-1×4+3n.
(n+1)(n+2)/1 +(n+2)(n+3)/1 +(n+3)(n+4)/1
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)
证明:1+2C(n,1)+4C(n,2)+...+2^nC(n,n)=3^n .(n∈N+)
如果,n是大于2的整数,计算1/(n-1)(n-2)+1/(n-2)(n-3)+1/(n-3)(n-4)+……+1/(n
若n为正整数,求1/n(n+1)+1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)+.+1/
求极限 lim(n->无穷)[(3n^2-2)/(3n^2+4)]^[n(n+1)]
求lim(n+1)(n+2)(n+3)/(n^4+n^2+1)
一道极限题,lim[n^2(2n+1)]/(n^3+n+4)n->∞
lim 9^n+4^n+2/5^n-3^2n-1 n趋于无穷大时