1. (1/ sin x + 1/ tan x )² = 1 + cos x /1- cos x
2. sin^6 x + cos ^6 x = 1-3 sin² x cos² x
3. (sin² x cos^4 x + sin^4 x cos² x ) tan² x = cos ^4 x
F.3 trigonometry
2010-05-23 12:53 am
回答 (2)
2010-05-23 1:39 am
✔ 最佳答案
Please see the following:圖片參考：http://img4.imageshack.us/img4/9694/95078948.png
2010-05-22 17:39:49 補充：
http://img4.imageshack.us/img4/9694/95078948.png
2010-05-23 1:23 am
1.)
L.H.S. = (1/sinx + 1-tanx)^2
= (1+cosx)^2 / (1+cosx)(1-cosx)
= (1+cosx)/(1-cosx)
= R.H.S.
L.H.S. = (1/sinx + 1-tanx)^2
= (1+cosx)^2 / (1+cosx)(1-cosx)
= (1+cosx)/(1-cosx)
= R.H.S.
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https://hk.answers.yahoo.com/question/index?qid=20100522000051KK01054