[질문] *특삼각함수공식정리해주세요~ 수2에서여

sin(a+b)=sinacosb+cosasinb, sin(a-b)=sinacosb-cosasinb, cos(a+b)=cosacosb-sinasinb, cos(a-b)=cosacosb+sinasinb tan(a+b)=(tana+tanb)/(1-tanatanb)