如何证明 tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-z)tan(z-x)

如何证明 tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-z)tan(z-x) 证明:tan(x+y)tan(x-y)=tan②x-tan②y/1-tan②xtan②y②表示平方 证明tan(x+y)+tan(x-y)=sin2x/cos^2x-sin^2y 如何证明 tan x=y时,如y是有理数,x是无理数? 求证tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-a)tan(z-x) tan(x+y)= 如果y=tan(x),如何证明y'''=2(1+y^2)(1+3y^2) 求证tan(x+y)*tan(x-y)=tan^2x-tan^2y/1-tan^2xtan^2y 化简,tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-z)tan(z-x)…请问怎么化?遇到类型题如何考虑解决? 求证tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-z)tan(z-x)tan(x-y)+tan(y-z)怎么化成tan〔（x-y）+(y-z)〕? tan(x+y)等于什么? y=tan|x|值域 y=tan(x平方) 证明sinx+cos(x+y)siny/cosx-sin(x+y)siny=tan(x+y) y=tan^2 x +2tan x如何求该函数最小值? 三角函数（请写出过程）求证：tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-z)tan(z-x) 证明tan^2x=2*tan^2y+1,求证sin^2y=2sin^2x-1 tan等于x/y还是y/x