tan(a+b)=(tana+tanb)/(1-tanatanb)
tan(π/6)=(tana+tanb)/(1-tanatanb)
√3/3=(tana+tanb)/(1-tanatanb)
√3(1-tanatanb)=3(tana+tanb)
√3(tanatanb-1)+3(tana+tanb)=0
tan(a+b)=(tana+tanb)/(1-tanatanb)
tan(π/6)=(tana+tanb)/(1-tanatanb)
√3/3=(tana+tanb)/(1-tanatanb)
√3(1-tanatanb)=3(tana+tanb)
√3(tanatanb-1)+3(tana+tanb)=0