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標題:
trigonometry
發問:
step by step thank 圖片參考：http://upload.lsforum.net/users/public/p47254x1248512r18p18.bmp 更新: to hung the ans. of q1 is 30 not 19
最佳解答:
1. Let BP = PQ = QC = r , Consider △BAC , tan 44° = AC / BC = AC / 3r ... (1) Consider △AQC , tan∠CAQ = QC / AC = r / AC ... (2) (1)x(2) : (tan 44°) tan∠CAQ = 1/3 , ∠CAQ = 19.0° 2. (2sinA - 3cosA) / (3sinA + 2cosA) = ( 2tanA - 3 ) / (3tanA + 2) = [ 2(-5/4) - 3 ] / [ 3(-5/4) + 2 ] = 22 / 7 2012-01-28 21:16:50 補充： I think your answer is wrong , where did you find the answer ?
my ans is19 too...
trigonometry
發問:
step by step thank 圖片參考：http://upload.lsforum.net/users/public/p47254x1248512r18p18.bmp 更新: to hung the ans. of q1 is 30 not 19
最佳解答:
1. Let BP = PQ = QC = r , Consider △BAC , tan 44° = AC / BC = AC / 3r ... (1) Consider △AQC , tan∠CAQ = QC / AC = r / AC ... (2) (1)x(2) : (tan 44°) tan∠CAQ = 1/3 , ∠CAQ = 19.0° 2. (2sinA - 3cosA) / (3sinA + 2cosA) = ( 2tanA - 3 ) / (3tanA + 2) = [ 2(-5/4) - 3 ] / [ 3(-5/4) + 2 ] = 22 / 7 2012-01-28 21:16:50 補充： I think your answer is wrong , where did you find the answer ?
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其他解答:my ans is19 too...
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