(2n-9)(2n-7)/(2n+5)(2n-3)
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
lim 9^n+4^n+2/5^n-3^2n-1 n趋于无穷大时
证明(1+2/n)^n>5-2/n(n属于N+,n>=3)
2^n/n*(n+1)
(2n-9)(2n-7)/(2n+5)(2n-3)
lim(3^2n+5^n)/(1+9^n)
[3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简
-n^3+8n^2-16n
化简(n+1)(n+2)(n+3)
已知888个连续正整数之和:n+(n+1)+(n+2)+(n+3)+(n+4)+(n+5)+(n+6)+(n+7)+··
如果正整数n使得[n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n=
1\n(n+3)+1\(n+3)(n+6)+1\(n+6)(n+9)=1\2 n+18 n为正整数,求n的值