cos30度等于多少

①cos30°=cos(π/6)=sin60°=sin(π/3)=√3/2;

②cos45°=cos(π/4)=sin45°=sin(π/4)=√2/2;

③cos60°=cos(π/3)=sin30°=sin(π/6)=½;

④cos90°=cos(π/2)=sin0°=0;

⑤cos0°=sin90°=sin(π/2)=1;