求证:sin(x-y)sin(x+y)/sin²xcos²y=1-cot²xtan²y

求证sin²x-sin²y=sin(x+y)sin(x-y) 求证:sin(x-y)sin(x+y)/sin²xcos²y=1-cot²xtan²y sin(x.y)中, sin(x)^y求导 求证tanx+tany/tanx-tany=sin(x+y）/sin(x-y) 求证cosx-cosy=-2sin （x+y/2）*sin （x-y/2） 求证sin^2x+sin^2y-sin^2x*sin^2y+cos^2x*cos^2y=1 y=1+sinπX是周期函数吗?求证 Mathematica y''+ sin(x) y=x 证明sin(x+y)sin(x-y)=sinx-siny y=sin根号x y=sinx+sin|x| sin(x+y)的导数 化简sin(2x-y)*sin y+cos(2x-y)*sin y 求证 cos*xcos*y + sin*xsin*y + sin*xcos*y + xin*ycos*x = 1cos*xcos*y + sin*xsin*y + sin*xcos*y + sin*ycos*x = 1注意：[*] 的意思是 [ ^2 ]写下左右过程.. 求证tanx+tany/tanx-tany=sin（x+y）/sin（x-y）（详细步骤） 证明tan^2x=2*tan^2y+1,求证sin^2y=2sin^2x-1 tan方x=2tan方y+1,求证sin方y=2sin方x-1