1 + 2[sin(2x)/2 - 3^(1/2)cos(2x)/2] = 1 + 2sin(2x - π/3) 为什么
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
(1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x
化简 1/2cos x-根号3/2sin x 根3sin x+cos x
三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
已知fx=2/√3sin 2x-2/1[cos^x-sin^x]-1
化简2sin^2[(π/4)+x]+根号3(sin^x-cos^x)-1
证明成立:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).
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).
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)