why cos 70 = -cos 110?
回答 (1)
2011-03-20 12:28 am
You need to look at the full definition of the cosine function to know why.
http://www.youtube.com/watch?v=ZffZvSH285c
http://www.youtube.com/watch?v=ZffZvSH285c
收錄日期: 2021-04-23 23:30:38
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110319162300AAHfpzz