题目
题型:不详难度:来源:
a |
b |
x |
y |
a |
b |
a |
b |
|
x |
A.
| B.
| C.
| D.7 |
答案
|
x |
a |
b |
又∵|
a |
b |
a |
b |
∴
x |
a |
b |
a |
a |
b |
b |
∴|
x |
2 |
故选A.
核心考点
试题【已知向量a,b,x,y满足|a|=|b|=1,a•b=0,且a=-x+yb=2x-y,则|x|等于( )A.2B.5C.3D.7】;主要考察你对平面向量数量积的运算等知识点的理解。[详细]
举一反三
BM |
AM |
CM |
CA |
A.4+
| B.2
| C.7 | D.9 |
a |
b |
x |
y |
a |
b |
a |
b |
|
x |
A.
| B.
| C.
| D.7 |
|
x |
a |
b |
a |
b |
a |
b |
x |
a |
b |
a |
a |
b |
b |
x |
2 |
BM |
AM |
CM |
CA |
A.4+
| B.2
| C.7 | D.9 |