Trigonometry

👨🏻‍🏫 學術台數學

知識就是力量

2010-04-27 3:23 am

圖片參考：http://img442.imageshack.us/img442/547/screenhunter02apr261921.png

http://img442.imageshack.us/img442/547/screenhunter02apr261921.png

更新1:

To 超凡學生 Consider the case of cos x = 1/2 you miss out one more solution.

更新2:

Im sorry I made a mistake, you are right in this case. But consider cos x = -1, you are not get the answer correct~

回答 (2)

用戶7639

2010-04-27 3:34 am

✔ 最佳答案

圖片參考：http://j.imagehost.org/0136/ScreenHunter_08_Apr_26_19_32.gif

http://j.imagehost.org/0136/ScreenHunter_08_Apr_26_19_32.gif

2010-04-30 22:58:04 補充：
cosx = -1 ,
x= 2npi 正負 pi
= (2n 正負1)pi

👍 0 👎 0

hung

2010-05-01 5:35 am

cosx = -1 ,
x= 2npi + - pi
= (2n+ -1)pi

👍 0 👎 0

收錄日期: 2021-04-23 18:26:59
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100426000051KK01169

檢視 Wayback Machine 備份