sin x *cos y-cos x*siny 用Mathematica怎么化简

y=2cos x (sin x+cos x) y=(sin x + COS x)^2 化简sin(x+y)sin(x-y)-cos(x+y)cos(x-y)的结果是? 化简sin(x+y)cos(x-y)+cos(x+y)sin(x-y) sin(x-y)sin(x+y)-cos(x-y)cos(x+y) 证明COS（X+Y）COS（X-Y）=COS^2X-SIN^2Y 证明cos(x+y)cos(x-y)= cos^2(x)-sin^2(y) 参数方程x=cos(sin+cos)y=sin（cos+sin）化为普通方程 化简sin (x+y)sin x +cos (x+y)cos x= sin(x+y)sin(x-y)=k,求cos^2x-cos^2y 已知Sin x+Sin y=1/2,Cos x+Cos y=根号3/3,求S求Sin(x-y)/2 matlab如何绘制参数函数的图像?x=cos(s)*cos(t);y=cos(s)*sin(t);z=sin(s);其中0 请问sin（x+y）cos y-cos（x+y）sin y得多少 cos(x+y)*cos(x-y)=cos*cosx+sin*siny 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) y=(sin(x)-1)/(cos(x)+(cos(x))/(sin(x)+1)的奇偶性 y=Sin x +Cos x + Sin x * Cos x 的值域是多少? y = (cos x - sin x ) / ( cos x + sin x) 的最小正周期