sin(-110°)大,sin(-820°)小.
sin(-820°)可化简为sin(-100°),-820°+720°=-100°
sin(-110°)等同于sin(250°),sin(-100°)等同于sin(260°),同在第三区间,而第三区间是递减区间,所以前者打后者小!
也可根据sin曲线图来判断更简单!