求证:1-1/2+1/3-1/4+1/5-1/6+……+1/(2n-1)=1/(n+1)+1/(n+2)+……+1/2n
求证1²+2²+3²+……+n²=(1/6*n(n+1)(2n+1))/n(n为
求极限 lim n[1/(n^2+1)+1/(n^2+2^2)+……+1/(n^n+n^n)] (n趋向于无穷大,n^n
组合:C(n,0)+C(n,1)+……+C(n,n)=n^2
用数学归纳法证明:(n+1)+(n+2)+…+(n+n)=n(3n+1)2
证明不等式:(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n
(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
求证Cn0Cn1+Cn1Cn2+……+Cn(n-1)Cnn=(2n)!/(n-1)!(n+1)!
求证1×2+2×3+3×4+…+n(n+1)=13n(n+1)(n+2)
求证1^2/1.3+2^2/3.5+…+x^2/((2n-1)(2n+1))=(n(n+1)/(2(2n+1)),n属于
用数学归纳法证明(n+1)(n+2)…(n+n)=2^n*1*3*…*(2n-1)(n∈N+)在线等
用数学归纳法证明(n+1)(n+2)…(n+n)=2^n*1*3*…*(2n-1)(n∈N+)
当n为正偶数,求证n/(n-1)+n(n-2)/(n-1)(n-3)+...+n(n-2).2/(n-1)(n-3)..