问题 填空题
平面直角坐标系中,O为坐标原点,已知两点A(2,1),B(x,y)若点B满足
OA
AB
,则点B的轨迹方程为______.
答案

依题意,

OA
=(2,1),
OB
=(x,y),

AB
=(x-2,y-1)

OA
AB
,∴(2,1)•(x-2,y-1)=0

∴2x+y-5=0

即点B的轨迹方程为2x+y-5=0

故答案为2x+y-5=0

单项选择题
单项选择题