f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
已知函数f(x)=2cos x sin(x+pai/6)-sin^2x+cos^2x.
已知函数f(x)=cos^4 x-2sin x cos x-sin^4 x
化简!f(x)=sin(pai-x)cos(3/2pai+x)+sin(pai+x)sin(3/2pai-x)
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
f(x)为奇函数,x>0,f(x)=sin 2x+cos x,则x
已知f(x)=cos^2x+sinxcosx g(x)=2sin(x+π/4)sin(x-π/4)
已知函数f(x)=cos(2x-π/3)+2sin(x-π/4)sin(x+π/4)=sin(2x-π/6) ,
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