第二十九届国际数学奥林匹克竞赛有一道非常难的预选题: 命题 设a_i】0,β_i】0(1≤n,n】1),且sum from i=1 to n a_i=sum from i=1 to n β_i=π. 证明:sum from i=1 to n cosβ_i/sina_i≤sum from i=1 to n ctga_i (1) (蒙古提供)
文摘第二十九届国际数学奥林匹克竞赛有一道非常难的预选题: 命题 设a_i】0,β_i】0(1≤n,n】1),且sum from i=1 to n a_i=sum from i=1 to n β_i=π. 证明:sum from i=1 to n cosβ_i/sina_i≤sum from i=1 to n ctga_i (1) (蒙古提供)