sin220°+cos210°+tan315°+2cos300°等于多少,

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sin220°+cos210°+tan315°+2cos300°等于多少,

sin220°+cos210°+tan315°+2cos300°等于多少,
sin220°+cos210°+tan315°+2cos300°等于多少,

sin220°+cos210°+tan315°+2cos300°等于多少,
sin220°=sin(-40)° cos210°=cos(-30)°=-cos30°=-√3/2 tan315°=tan(-45)°=-tan45°=-1 cos300°=cos60°=0.5 sin220°+cos210°+tan315°+2cos300° =sin(-40)°-√3/2-1+2×0.5 =-sin40°-√3/2

sin220°+cos210°+tan315°+2cos300° =-sin40°-cos30°-tan45°+2cos60° =-sin40°-√3/2-1+1 =-sin40°-√3/2