cos 2x(1-2sin^2 2x) + cos 4x (1+cos 2x)=
2cos x (sin x -cos x)+1
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
已知f(x)=sin(x/2) + cos(x/2) +[cos(x/2)]^2-1/2
化简f(x)=2cos(x/2)·(sin(x/2)+cos(x/2))-1
已知函数f(x)=2Cos x(Sin x-Cos x)+1
证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
化简 1/2cos x-根号3/2sin x 根3sin x+cos x
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
MATLAB画图,y=sin(x)*(cos(x)-1)/((2*sin(x.^2)+4*cos(x)).^0.5)-(