根号3tan70+根号3tan80-tan70tan80
问题描述:
根号3tan70+根号3tan80-tan70tan80
答
tan(70+80)=(tan70+tan80)/(1-tan70tan80)=-1/√3
1-tan70tan80=-√3*(tan70+tan80)
√3tan70+√3*tan80-tan70tan80=-1