１．已知通過A(p+1, 4)和B(p-1 , 3)的直線斜率是-3/2 , 求ｐ
２．已知A(4,2)、B(7,-1)和C(x,8)三點共一直線 ，求ｘ
３．已知P(3,y)、Q(6,1)、R(-3,4)三點共一直線 ，求y
斜率三條請幫忙
2010-03-28 2:53 am
回答 (2)
2010-03-28 3:49 am
✔ 最佳答案
1.)M_AB = -3/2
(3-4)/[(p-1)-(p+1)] = -3/2
2 = - 3[p-p-1-1]
2 = -3(-2)
2 = 6 ,which is impossible
Therefore, there is no solution for p.
2.)
M_AB = M_BC (Collinear)
(-1-2)/(7-4) = (8+1)/(x-7)
-3/3 = 9/(x-7)
7-x = 9
x = 2
3.)
M_PQ = M_QR (Collinear)
(1-y)/(6-3) = (4-1)/(-3-6)
(1-y)/3 = 3/(-9)
-9+9y = 9
9y = 18
y = 2
參考: Hope can help you^^”
2010-03-28 3:05 am
第1題有冇打錯??????!
收錄日期: 2021-04-23 20:42:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100327000051KK01169