sin(2x+45)=cos
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)
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
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
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
已知向量a=(cosωx-sinωx,sinωx),b=(-cosωx-sinωx,2√ 3cosωx),
向量m=(sin ωx+cos ωx,cos ωx)(ω>0),n=(cos ωx-sin ωx,2sin ωx),函数