无需下载.在线玩游戏:一道数学题,很简单,一时忘了怎么做
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根号3tan70+根号3tan80-tan70tan80
tan(70+80)=(tan70+tan80)/(1-tan70tan80)=-1/√3
1-tan70tan80=-√3*(tan70+tan80)
√3tan70+√3*tan80-tan70tan80=-1
=1
tan(70+80)=(tan70+tan80)/(1-tan70tan80)=-1/√3
1-tan70tan80=-√3*(tan70+tan80)
√3tan70+√3*tan80-tan70tan80=-1
=1