數學
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中四級數學-三角學(1)
2014-04-13 9:33 pm
回答 (2)
2014-04-13 10:20 pm
✔ 最佳答案
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http://www.fss.edu.hk/maths/formula/trigonometry.htm
http://www.fss.edu.hk/maths/formula/trigo%20II.htm
2014-04-13 9:53 pm
請先看意見欄的教學:
https://hk.knowledge.yahoo.com/question/question?qid=7014040900101
(a)
-1/tanθ = (5 - sinθ)/(-cosθ)
1/tanθ = (5 - sinθ)/cosθ
cosθ/sinθ = (5 - sinθ)/cosθ
cos²θ = (5 - sinθ)sinθ
1-sin²θ = 5sinθ - sin²θ
5 sinθ = 1
2014-04-13 13:54:53 補充：
(b)
先乘分母過左邊, 變成 (a) 的模樣~
用 (a) 的結果:
5 sinθ = 1
sinθ = 1/5
θ = 11.536959° or 180°-11.536959°
https://hk.knowledge.yahoo.com/question/question?qid=7014040900101
(a)
-1/tanθ = (5 - sinθ)/(-cosθ)
1/tanθ = (5 - sinθ)/cosθ
cosθ/sinθ = (5 - sinθ)/cosθ
cos²θ = (5 - sinθ)sinθ
1-sin²θ = 5sinθ - sin²θ
5 sinθ = 1
2014-04-13 13:54:53 補充：
(b)
先乘分母過左邊, 變成 (a) 的模樣~
用 (a) 的結果:
5 sinθ = 1
sinθ = 1/5
θ = 11.536959° or 180°-11.536959°
收錄日期: 2021-04-13 21:18:01
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140413000051KK00068