trigonometric relations f.2

👨🏻‍🏫 學術台數學

[匿名]

2010-05-16 10:33 pm

1 . simplify:: 1 - sinθcosθ/tanθ + sin^2θ/tan^2θ

2. given that :: sin(90度-θ)/tan(90度-θ) = cos(2θ+30度) ,, findθ

3. prove the identity :: sin^2θ-sin^4θ+cos^4θ 恆等於 cos^2θ

更新1:

第1題前面仲有個 1- 架~ 所以係 1 - sinθcosθ/tanθ + sin^2θ/tan^2θ

回答 (2)

STEVIE-G™

2010-05-16 10:47 pm

✔ 最佳答案

As follows:

圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/03-62.jpg

2010-05-16 14:47:44 補充：
http://i707.photobucket.com/albums/ww74/stevieg90/03-62.jpg

2010-05-16 15:36:46 補充：
嗯...
咁第1題去到第2步...
=(1-cos²@)+cos²@
=1

2010-05-16 15:37:52 補充：
=1-sin@cos@/(sin@/cos@)+sin²@/(sin²@/cos²@)
=1-cos²@+cos²@
=1

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匿名

2010-05-17 2:40 am

#1
1 - cos^2 @ + cos^2 @
= 1

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收錄日期: 2021-04-22 00:47:54
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