ans: x^2+y^2+6x-6y-47=0
更新1:
re: nelsonywm2000, why can i let the centre be(2t-9, t)??
coordinate geometry(circle)
2010-04-03 3:19 am
find the equation of the circle through the points (1,-4) and (5,2), and has its centre on the line x-2y+9=0.
ans: x^2+y^2+6x-6y-47=0
ans: x^2+y^2+6x-6y-47=0
回答 (1)
2010-04-03 3:35 am
✔ 最佳答案
===================================================圖片參考：http://img69.imageshack.us/img69/9866/26589513.png
2010-04-02 19:35:10 補充：
http://img69.imageshack.us/img69/9866/26589513.png
2010-04-02 21:33:29 補充：
先隨意設y=t
x-2t+9=0=> x=2t-9
也可設x=t,
t-2y+9=0=>y=(t+9)/2然後計算結果也會是一樣
收錄日期: 2021-04-23 23:21:16
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100402000051KK01417