(-1)^n *a

设a,n∈N*证明a^2n-(-a)^n≥(a+1)×a^n 因式分解:a^n+1+a^n+a^n-1 a^n+1+a^n-1-2a^n因式分解 a^n+2+a^n+1-a^n因式分解 a^n+2+a^n+1-3a^n因式分解 A(n,n)+A(n-1,n-1)=XA(n+1,n+1)求X a^n-1-a^n+1因式分解 计算a^n(a^n+1+a^n+a^n-1)-a^n-1(a^n+1+a^n-a^n-1) lim((n+1)^a-n^a) (0 (a^n+1)-(a^n-2)等于 排列组合的证明A(n+1,n+1)-A(n,n)=n²A(n-1,n-1) 求通项公式.a(n+1)=2a(n)+n 求极限,N趋向无穷,n^2 （(a+1/n)^(1/n)-a^(1/n)）n^2 *((a+1/n)^(1/n)-a^(1/n)) 数列a(n)=n (n+1)(n+2)(n+3),求S(n) (-1)^n*a (-1)^n *a (3a^n+1+6a^n+2-9a^n)/3a^n-1 (6a^n+2 +3a^n+1 -9a^n)/3a^n-1