计算1^2-2^2+3^2-4^2+5^2-6^2+...+(2n-1)^2-(2n)^2
计算:n(n+1)(n+2)(n+3)+1
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
计算9^n*(1/27)^n+1*3^n+2
用夹逼准则和重要极限两种方法计算极限lim(2^n+3^n+4^n+5^n+6^n)^(1/n)n趋近于...
计算:C(1,n)+2C(2,n)+3C(3,n) + … + nC(n,n)
初一计算:(m+5n)(m-n)-6(m+2n)(n-3n)?
计算级数 ∑n/2^(n-1)
2^n/n*(n+1)
[3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简
Sn=n(n+2)(n+4)的分项等于1/6[n(n+2)(n+4)(n+5)-(n-1)n(n+2)(n+4)]吗?
如果,n是大于2的整数,计算1/(n-1)(n-2)+1/(n-2)(n-3)+1/(n-3)(n-4)+……+1/(n
计算1/(m-n)-1/(m+n)-2n/(m^2+n^2)-4n^3/(m^4+n^4)-8n^7/(m^8+n^8)