cos(-5π/6)=cos(5π/6)=cos(π-π/6)=-cosπ/6
cos(-3π/4)=cos(3π/4)=cos(π-π/4)=-cosπ/4
cosπ/6=1/2
cosπ/4=√2/2
cosπ/6-cosπ/4
即cos(-5π/6)>cos(-3π/4)
请及时点击右下角的【好评】按钮