cos^4x-sin^4x 2sin^2x=
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
(1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x
已知函数f(x)=cos^4 x-2sin x cos x-sin^4 x
用cos x表示sin^4 x -sin^2 x +cos^2 x
三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
sin x + cos x = √2 * sin (x + Pi/4)
sin(5x)-sin(3x)= 根号2cos(4x)
求函数fx=(sin^4x+cos^4x+sin^2x*cos^2x)/(2-sin2x)