三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
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
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
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
证明等式:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).成立
求证 tan(2π-X)sin(-2π-X)cos(6π-X)/ sin(X+3π/2)*cos(X+3π/2)=-ta
化简(1)√3sin x+cos x (2)√2(sin x-cos x) (3)√2cos x-√6sin x
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
已知函数f(x)=cos(2x-π/3)+2sin(x-π/4)sin(x+π/4)=sin(2x-π/6) ,
求证 cos^8(x)-sin^8(x)=cos2x【1-1/2sin^2(2x)】
求证 sinˇ4X+sin²Xcos²X+cos²X = 1