four point A(1,2),B(7,-5),C(-2,-10),D(-9,-1) are given
E is another point in the coordinate plane so that ABCE is a parallelogram.
(i) Find the mid point ofAC. Hence find the coordinates of E.
(ii) If another point F is added so that ACDF form another parallelogram. Find the coordinates of F.
coordinate geometry
2008-08-03 5:08 pm
回答 (1)
2008-08-03 5:19 pm
✔ 最佳答案
(i) mid-pt of AC=[(1-2)/2,(2-10)/2]
=(-1/2,-4)
mid-pt of BE=mid-pt of AC
let the coor of E be (x,y)
(x 7)/2=-0.5
x=-8
(y-5)/2=-4
y=-3
so E=(-8,-3)
(ii) mid -pt of AD
=[(1-9)/2,(2-1)/2]
=(-4,1/2)
mid-pt of AD=mid-pt of CF
let the coor of F be (p,q)
(p-2)/2=-4
x=-6
(q-10)/2=1/2
q=11
so F =(-6,11)
參考: me
收錄日期: 2021-04-23 21:22:04
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