Please answer the following questions and please don't use some stupid methods to do them. Thanks a lot!
Given that the two straight lines L1: (a+1)x-2y-4=0 and L2: 4x+(a+3)y=0 are perpendicular to each other,
(a) find the value of a,
(b) find the coordinates of the intersection P of L1 and L2,
(c) if L is the straight line passing through P and perpendicular to L3: x-2y=0, find the equation of L.
Urgent! F.5 Maths
2008-09-14 10:41 pm
回答 (1)
2008-09-14 10:53 pm
✔ 最佳答案
(a) slope of L1 x Slope of L2 = -1=> (a+1)/2 x -4/(a+3) = -1
=> (-4a-4)/(2a+6) = -1
=> 4a + 4 = 2a + 6
=> a = 1
(b) L1: 2x - 2y - 4 = 0
L2: 4x + 4y = 0
(c) 2xL1+L2:
8x - 8 = 0
=> x = 1
=> y = -1
P = (1,-1)
Slope of L3 = 1/2
=> Slope of L = -2
i.e. L : y = -2x + 1
參考: 自己
收錄日期: 2021-04-24 23:21:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080914000051KK01183