求证sin^4x-cos^4x=2sin^2x-1
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
求证 cos^8(x)-sin^8(x)=cos2x【1-1/2sin^2(2x)】
求证 sinˇ4X+sin²Xcos²X+cos²X = 1
求证:sin(π/4+x)/sin(π/4-x)+cos(π/4+x)/(π/4-x)=2/cos2x
(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
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
求证sin^2x+sin^2y-sin^2x*sin^2y+cos^2x*cos^2y=1
MATLAB画图,y=sin(x)*(cos(x)-1)/((2*sin(x.^2)+4*cos(x)).^0.5)-(
已知sin X+cos X=m,|m|小于等于根号2且|m|不等于1,求sin X^3+cos X^3,sin X^4+