sin(30度+x/2)=cos什么
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
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).
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
SIN(30度-X)=1\3,则COS(120度+2X)等于多少.
若f(cos x)=cos 2x,则f(sin 15度)的值?
函数y=sin(x/3)*cos(2x/3)+cos(x/3)*sin(2x/3)(x∈R)的图像关于什么对称
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y