解不等式:[n/(n+1)]﹙3/4﹚^n≥[﹙n+1﹚/﹙n+2﹚](3/4)^n,
解不等式:[n/(n+1)]﹙3/4﹚^n≥[﹙n+1﹚/﹙n+2﹚](3/4)^n,
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
化简:1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)
(n+1)(n+2)/1 +(n+2)(n+3)/1 +(n+3)(n+4)/1
证明不等式 1+2n+3n
证明:1+2C(n,1)+4C(n,2)+...+2^nC(n,n)=3^n .(n∈N+)
求证不等式(3^n-4^n)大于等于4^(n-1)其中n属于正整数
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
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/
lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2)
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)