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更新1:
(b)答案係(3 ± √ 17)/4
f.4 maths (20點)
2011-05-22 6:01 pm
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回答 (1)
2011-05-22 6:41 pm
✔ 最佳答案
(a) 設兩根a,ba + b = 3/2
ab = 4tanϑ/2 = 2tanϑ
(a - b)^2 = 17/4
(a + b)^2 - 4ab = 17/4
9/4 - 8tanϑ = 17/4
tanϑ = -1/4
(b) 2x^2 - 3x + 4tanϑ = 0
2x^2 - 3x - 1 = 0
x = (3 ± √ 13)/4
收錄日期: 2021-04-26 14:56:11
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110522000051KK00232