化简:sin^4 x-sin^2 x+cos^2 x
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
化简 cos^2(x)*sin^2(x)-sin^2(x)
化简 cos^(2)(x)*sin^(2)(x)-sin^(2)(x)
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
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
化简 1/2cos x-根号3/2sin x 根3sin x+cos x
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
用cos x表示sin^4 x -sin^2 x +cos^2 x
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
化简cos^4x+sin^2xcos^2x+sin^2x
化简2sin^2[(π/4)+x]+根号3(sin^x-cos^x)-1