y=(sin x + COS x)^2

sin(x+y)sin(x-y)=k,求cos^2x-cos^2y 证明COS（X+Y）COS（X-Y）=COS^2X-SIN^2Y 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) y =(cos^2) x - sin (3^x),求y' Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y) 求导y=(1+sin^2 x)/(cos(x^2)) y=sin^2x+sinxcoswx+cos^2x 化简 化简y=(cos x)^2+sin x -2 谢谢 设sin(x+y)sin(x-y)=m,则cos^2x-cos^2y的值 已知函数y=(sin x+ cos x)(sin x+cos x)+2cos x*cos x ,求它的递减区间 求函数y =cos 2x +sin 2x /cos 2x -sin 2x 的最小正周期 y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)的最值 用向量解