已知三點A(1,-1),B(3,3),C(4,5)求証這三點在同一直綫上
請解式.....寫下詳細過程
急...一題几何
2007-07-10 1:45 am
回答 (2)
2007-07-10 1:49 am
✔ 最佳答案
Slope of AB = ( 3 + 1 ) / ( 3 - 1 ) = 2Slope of BC = ( 5 - 3 ) / ( 4 - 3 ) = 2
Since the slope of AB is equal to the slope of BC, the three points are on the same line.
參考: My Maths Knowledge
2007-07-10 1:51 am
AB斜率
= -1-3/1-3
=-4/-2
=2
BC斜率
=3-5/3-4
=-2/-1
=2
AC斜率
=-1-5/1-4
=-6/-3
=2
由於AB斜率=BC斜率=AC斜率=2
所以ABC三點在同一直綫上
2007-07-09 17:52:13 補充：
上面未証AC斜率
= -1-3/1-3
=-4/-2
=2
BC斜率
=3-5/3-4
=-2/-1
=2
AC斜率
=-1-5/1-4
=-6/-3
=2
由於AB斜率=BC斜率=AC斜率=2
所以ABC三點在同一直綫上
2007-07-09 17:52:13 補充：
上面未証AC斜率
參考: MYSELF
收錄日期: 2021-04-12 20:07:20
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