n^4 2n^3 3n^2 2n 2 化简
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)
[3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简
化简(n+1)(n+2)(n+3)
(n+1)(n+2)/1 +(n+2)(n+3)/1 +(n+3)(n+4)/1
(m-n)2(n-m)3(n-m)4化简
-n^3+8n^2-16n
证明:1+2C(n,1)+4C(n,2)+...+2^nC(n,n)=3^n .(n∈N+)
如果正整数n使得[n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n=
lim[(n+3)/(n+1))]^(n-2) 【n无穷大】
计算:n(n+1)(n+2)(n+3)+1
(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