问题
选择题
已知O为坐标原点,
|
答案
设C(x,y)则
=AC
-OC
=(x+3,y-1); OA
=BC
-OC
=(x,y-5);OB
=AB
-OB
=(3,4)OA
∵
∥AC
,OA
⊥BC AB
∴-3(y-1)=x+3 3x+4(y-5)=0
解得x=-3 y= 29 4
故选C
已知O为坐标原点,
|
设C(x,y)则
=AC
-OC
=(x+3,y-1); OA
=BC
-OC
=(x,y-5);OB
=AB
-OB
=(3,4)OA
∵
∥AC
,OA
⊥BC AB
∴-3(y-1)=x+3 3x+4(y-5)=0
解得x=-3 y= 29 4
故选C