若sin x/2 - cos x/2 = 1/3,则sin x=?
若sin x/2-cos x/2=1/3,则sin x=
若sin x/2 - cos x/2 = 1/3,则sin x=?
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
已知fx=2/√3sin 2x-2/1[cos^x-sin^x]-1
证明成立:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
已知(1+sin x)/cos x=1/2,则cos x/(sin x-1)的值是