A,B,C能构成三角形,则三点不再一条直线上
当三点一线时:
AB=OB-OA=(6,-3)-(3,-4)=(3,1)
BC=OC-OB=(-x-1,-y)
AB=rBC
(3,1)=(-rx-1r,-yr)
3=-rx-1r=-(x+1)r
1=yr
相除:3=-(x+1)/y
y=-(1/3)x-(1/3)
当y≠-(1/3)x-(1/3)时,A,B,C能构成三角形
A,B,C能构成三角形,则三点不再一条直线上
当三点一线时:
AB=OB-OA=(6,-3)-(3,-4)=(3,1)
BC=OC-OB=(-x-1,-y)
AB=rBC
(3,1)=(-rx-1r,-yr)
3=-rx-1r=-(x+1)r
1=yr
相除:3=-(x+1)/y
y=-(1/3)x-(1/3)
当y≠-(1/3)x-(1/3)时,A,B,C能构成三角形