解不等式n(n+1)(2n-1)

证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 解不等式n(n+1)(2n-1) 证明不等式 1+2n+3n 不等式求解法：n*(n+1)/2 证明不等式：(1/n)的n次方+(2/n)的n次方+……+(n/n)的n次方 数学不等式证明题n=1,2,……证明：(1/n)^n+(1/2)^n+……+(n/n)^n第二个是(2/n)^n 使不等式1/n(n+1)+1/(n+1)(n+2)+...+1/(2n-1)2n 2^n/n*(n+1) 解不等式：[n/(n+1)]﹙3／4﹚^n≥[﹙n+1﹚/﹙n+2﹚](3/4)^n, 1.使不等式1/(n+1)+1/(n+2)+1/(n+3)+...+1/(2n+1) 证明对任意正整数n,不等式ln(1/n+1)>1/n^2-1/n^3 求满足不等式C(n,1)+2C(n,2)+……+nC(n,n)