Urgent Question(19) ^_^
回答 (1)
2007-08-19 10:01 am
✔ 最佳答案
(cosӨtanӨ)^2 + (sinӨ/tanӨ)^2 = (cosӨ x sinӨ/cosӨ)^2 + (sinӨ x cosӨ/sinӨ)^2
= (sinӨ)^2 + (cosӨ)^2
= 1
** 1/tanӨ = cosӨ/sinӨ**
收錄日期: 2021-04-15 14:49:53
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070819000051KK00517