骑行双肩包品牌:求证tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-a)tan(z-x)

求证tan(x-y)+tan(y-z)+tan(z-x)=tan(x-y)tan(y-a)tan(z-x) 7sinx=3sin(x+y) 求证:2tan[(2x+y)/2]=5tan(y/2) tan(x+y)=0.4,tan(y-45°)=0.25,则tan(x+45°)=?要过程 已知x,y,z为正实数,y*y=x*z,求证:x*x+y*y+z*z>(x-y+z)*(x-y+z) y=tan(x/2+pi/3)？ 5cos(x-y/2)+7cos(y/2)=0求tan(x/2)*tan[(x-y)/2] 设x.y.z满足3x=4y=6z（x.y.z都是指数）求证 求证：tanA+B/2*tanA-B/2=tan(y/2)^2 求 y＝tan A-sinA y=tan(sinx)的周期是多少？