1.If A, B and C are acute angles and cot A = 2 , cot B = 5 and cotC = 8 , find (A + B + C) without using calculators.
2. In ㄥABC , Suppose that sin A = sin(B + C) and tan B = cos(B - C) / [sin A - sin(B - C)]
(i) show that cos Bcos(B +C) = 0 ,
(ii) hence, prove that A=兀/2
Functions of Compound Angles
2012-08-09 5:02 am
回答 (1)
2012-08-09 6:21 am
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參考: miraco
收錄日期: 2021-05-02 10:58:43
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