若sin(x+3п)cos(x-п)=2a+1,求实数a的取值范围.

已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=? 2sin^2x - 5sin x cos x=3 cos^2x,求X, 若cos x-sin x = 0.5,则cos^3 x-sin^3 x = 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) 证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4 sin^3 x -cos^3 x sin^3 x -cos^3 x =(sin x -cos x )(sin^2 x +sin x*cos x +cos^2 x )问下这个是个公式还是什么?怎么样算出来的? 若F(sin x)=3-cos 2x 则F（cos x）=? 若sin x/2 - cos x/2 = 1/3,则sin x=? 若sin x/2-cos x/2=1/3,则sin x= 已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x y=2cos x (sin x+cos x) 若sin(x+3п)cos(x-п)=2a+1,求实数a的取值范围. 若sin(x+3п)cos(x-п)=2a+1,求实数a的取值范围. sin(x/2)cos(x/2)= sin[cos^2(x^3+x)],求导 y=(sin x + COS x)^2 求证(3-sin^4 x-cos^4 x)/2cos^2 x=1+tan^2 x+sin^2 x Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)