sin(x+15°)=1/3 则cos(x+105°)=?

sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简 若sin x/2-cos x/2=1/3,则sin x= 若sin x/2 - cos x/2 = 1/3,则sin x=? 设f(x)=[2cos^3 x-sin^2 (360°-x)+2sin(90°+x)+1]/2+2cos^2 (180° sin（sin（sin（sin（x）=cos（cos（cos（cos（x）,X等于多少? 求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x). Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y) 若SIN X*COS X =1/3,已知0 已知(1+sin x)/cos x=1/2,则cos x/(sin x-1)的值是 cos x sin x=3,求cos x+sin x 证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)