求证:3/2-1/n+1
求证:3/2-1/n+1
求证1/(n+1)+1/(n+2)+.+1/(3n+1)>1 [n属于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)..
求证1+1/2+1/3+...+1/n>In(n+1) (n属于N+)
求证:1+1/2+1/3+...+1/n>In(n+1)+n/2(n+1) (n属于N+)
数学定理证明求证2^n-1=2^n-1+2^n-2+2^n-3+.+2^n-n
求证c(n,1)+2c(n,2)+3c(n,3)+...+nc(n,n)=n2^(n-1)
(1) 求证:n
设n∈N,n>1.求证:logn (n+1)>log(n+1) (n+2)
求证:1/(n+1)+1/(n+2)+1/(n+3)+...+1/(3n+1)>25/24(n是正整数)
求证1×2+2×3+3×4+…+n(n+1)=13n(n+1)(n+2)
求证 1/(n+1)+1(n+2)+.+1(3n+1)>1