1.输入有误
sin50°+cos50°
=√2*【sin50°*(√2/2)+cos50°*(√2/2)】
=√2*(sin50°cos45°+cos50°sin45°)
=√2sin95°
=√2sin85°
sin65°+cos65°
=√2*【sin65°*(√2/2)+cos65°*(√2/2)】
=√2*(sin65°cos45°+cos65°sin45°)
=√2sin110°
=√2sin70°
∵ √2sin85°>√2sin85°
∴ sin50°+cos50°>sin65°+cos65°
又∵ logsina (x)是减函数
∴ P