化简sin^4x-sin^2+cos^2

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) 化简cos^4x+sin^2xcos^2x+sin^2x 化简2sin^2[(π/4)+x]+根号3（sin^x-cos^x）-1 sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos (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 化简sin(2x-y)*sin y+cos(2x-y)*sin y 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