請各位高手幫小妹解答一下。
CE-92-5
L1 is the line passing through the point A (10,5) and perpendicular to the line L2: x-2y+5=0.
(a).Find the equation of L1.
(b).Find the intersection point of L1 and L2.
CE-00-9
Let L be the straight line passing through (-4,4) and (6.0)
(c).If L intersects the y-axis at C, find the coordinates of C
謝謝！
Maths CE-92-5,CE-00-9 Long Q.
2008-05-13 3:47 am
回答 (1)
2008-05-13 4:37 am
✔ 最佳答案
a)m of L2 = 1/2
mL1 x mL2 =-1
mL1 = -2
y-5= -2(x-10)
y-5=-2x+20
L1 : 2x+y-25=0
b)
2x+y-25=0 -----i
x-2y+5=0 -------ii
x=2y-5 ------iii
sub iii into i
2(2y-5)+y-25=0
5y-35=0
y=7
x=2(7)-5
x=9
intersection pt = (9,7)
CE-00-9
L: (y-4)/(x+4) = (0-4)/(6+4)
10y-40= - 4x-16
10y+4x-24=0
10y=-4x+24
y=0.4x+2.4
by y=mx+c
c=2.4
coordinates of C is (0,2.4)
收錄日期: 2021-04-13 15:33:40
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