化简 (tan(a+b)-tana-tanb)/(tanatan(a+b))

问题描述:

化简 (tan(a+b)-tana-tanb)/(tanatan(a+b))

(tan(a+b)-tana-tanb)/(tanatan(a+b))=((tana+tanb)/(1-tanatanb)-(tanatanb))/(tana*(tana+tanb)/(1-tanatanb))
=tanb