向量![]()
[ ]
|
A . |
B . |
|
C .2 |
D .±2 |
若![]()
[ ]
|
A .(2,6) |
B .(1,6) |
|
C .(1,5) |
D .(2,5) |
已知![]()
[ ]
|
A .(12,11) |
B .(16,-11) |
|
C .(-16,11) |
D .(-16,-11) |
若
共线,则有
[ ]
|
A . |
B . |
|
C . |
D . |
已知![]()
[ ]
|
A .(4,2) |
B .(-4,-2) |
|
C .(2,1)或(-2,-1) |
D .(4,2)或(-4,-2) |
=(
[ ]
|
A .(1,7) |
B .(-1,7) |
|
C .(7,1) |
D .(-1,-7) |