數學問題?幫個忙!!?
回答 (1)
2020-11-28 9:33 pm
✔ 最佳答案
令 x = DE = EF, y = cF.則
(1) y^2 + (8-x)^2
= CF^2 + EC^2
= EF^2
= x^2
(2) 8^2 + (17-y)^2
= AB^2 + BF^2
= AF^2 = AD^2
= 17^2
由 (2) 得
y^2 - 34y + 64 = 0
= (y-2)(y-32)
因 0 < y < 17, 故 y = 2.
將 y 值代入 (1) 並化簡, 得
68 - 16x = 0
故 DE = x = 17/4
收錄日期: 2021-05-04 02:34:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20201128120117AAu79uC