向量BC(-6,-3)
设D(x,y) AD(x-2,y+1)
-6(x-2)-3(y+1)=0
2x+y=3 y=3-2x
BD=kBC
(x-3,y-2)=k(-6,-3)
x-3=-6k y-2=-3k
x-3/y-2=2
x-3=2(3-2x-2)
x=1 y=1
D(1,1) AD(-1,2)
向量BC(-6,-3)
设D(x,y) AD(x-2,y+1)
-6(x-2)-3(y+1)=0
2x+y=3 y=3-2x
BD=kBC
(x-3,y-2)=k(-6,-3)
x-3=-6k y-2=-3k
x-3/y-2=2
x-3=2(3-2x-2)
x=1 y=1
D(1,1) AD(-1,2)