1)sin250°=sin(180°+70°)=-sin70°
sin260°=sin(180°+80°)=-sin80°
sin70°-sin80°
所以有;sin250°>sin260°
2)cos515°=cos(540°-25°)=-cos25°
cos530°=cos(534°-10°)=-cos10°
cos25°-cos10°
所以有:cos515°>cos530°
1)sin250°=sin(180°+70°)=-sin70°
sin260°=sin(180°+80°)=-sin80°
sin70°-sin80°
所以有;sin250°>sin260°
2)cos515°=cos(540°-25°)=-cos25°
cos530°=cos(534°-10°)=-cos10°
cos25°-cos10°
所以有:cos515°>cos530°