计算3/1*4+3/4*7+3/7*10+...+3/(3n-5)(3n-2)+3/(3n-2)(3n+1)
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^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)
计算:n(n+1)(n+2)(n+3)+1
lim(1/n^2+4/n^2+7/n^2+…+3n-1/n^2)
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)+··
化简:1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)
(n+1)(n+2)/1 +(n+2)(n+3)/1 +(n+3)(n+4)/1
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
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...
[3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简
lim 9^n+4^n+2/5^n-3^2n-1 n趋于无穷大时
计算(1×2×3+2×4×6+…+n×2n×3n)÷(1×3×5+2×6×10+…+n×3n×5n)