Prove the following:
a) (Sin x + sin 2x) / (1 + cos x + cos 2x ) = tan x
b) Cos 3A = 4 cos^3 A - 3cos A
c) Tan 3A = 3 tan A - tan^3 A / 1- 3 tan^2 A
Maths唔識抵死題(QUICK)
2010-10-06 6:59 am
回答 (1)
2010-10-06 7:40 am
收錄日期: 2021-04-23 20:42:32
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https://hk.answers.yahoo.com/question/index?qid=20101005000051KK01667