方程 Y_2)=(X+5)+3怎么算

两个未知数,一个方程,有无数个解
y=x+10
任意取一个x,就有一个y

左边=(sina/cosa*sin2a/cos2a)/(sin2a/cos2a-sina/cosa)-√3(cos2a-sin2a)
上下乘cosacos2a
=(sinasin2a/(sin2acosa-sinacos2a)-√3(cos2a-sin2a)
=(sinasin2a)/sin(2a-a)-√3cos2a
=sin2a-√3cos2a
=2(sin2a*1/2-cos2a√3/2)
=2(sin2acosπ/3-cos2asinπ/3)
=2sin(2a-π/3)
=右边
命题得证