sin(25π/12)cos(11π/6)-cos(25π/12)sin(11π/6)的值是

sin(25π/12)cos(11π/6)-cos(25π/12)sin(11π/6)的值是 化简sin（25π/12）cos（11π/6）-cos（11π/12）sin（5π/6）的值是 （sinπ/24)(cosπ/24)(cosπ/12) （sinπ/24)(cosπ/24)(cosπ/12) sinπ/12*cosπ/12=? 求值：sin(π/12)+cos(π/12) sin(π/12)-cos(π/12)= cos*π/12—sin*π/12 cosπ／12乘以sinπ／12 计算cosπ/12*sinπ/12 cosπ/6=(),sinπ=() cos5/12πcosπ/12+cosπ/12sinπ/6=? sin(α+π/3)+sinα=负5分之4根号3 α∈（-π/2,0）求cosα怎样从9/4*sin²α=9/4(1-cos²α)=3/4*cos²a+12/5*cosx+48/25化为cos²α+4/5*cosα-11/100=0呀sin(α+π/3)+sinα=-4√3/5sinαcosπ/3+cosαsinπ/3+sinα=-4√3/53/2*si （cosπ/12-sinπ/12)*(COSπ/12+sinπ/12)等于 (cosπ/12 -sinπ/12)(cosπ/12 +sinπ/12)等于 （cosπ/12-sinπ/12)(cosπ/12+sinπ/12)的值为 （cosπ/12 -sinπ/12）（cosπ/12 +sinπ/12）= (sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=