Prove that the line 2x + y + 2 = 0 is tangent to the circle
x^2 + y^2 + 6x +2y +5 = 0
收錄日期: 2021-05-03 05:43:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090905000051KK01666