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平面向量数量积的意义

> 对于非零向量 a 、 b ，下列命题中正确的是（　　） A． a • b =0⇒ a = 0 或 b = 0 B． a ∥ b ⇒ a 在 b 上的正射影的数量为| a | C． a ⊥ b ⇒ a • b =( a • b )2 D． a • c = b • c ⇒ a = b

问题：

发布时间：2024-09-08

对于非零向量

a

、

b

，下列命题中正确的是（　　）

A．

a

•

b

=0⇒

a

=

0

或

b

=

0

B．

a

∥

b

⇒

a

在

b

上的正射影的数量为|

a

|

C．

a

⊥

b

⇒

a

•

b

=(

a

•

b

)2

D．

a

•

c

=

b

•

c

⇒

a

=

b

参考答案：

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对于非零向量 a 、 b ，下列命题中正确的是（ ） A． a • b =0⇒ a = 0 或 b = 0 B． a ∥ b ⇒ a 在 b 上的正射影的数量为| a | C． a ⊥ b ⇒ a • b =( a • b )2 D． a • c = b • c ⇒ a = b

可能感兴趣的题目：

对于非零向量

a

、

b

，下列命题中正确的是（　　）

A．

a

•

b

=0⇒

a

=

0

或

b

=

0

B．

a

∥

b

⇒

a

在

b

上的正射影的数量为|

a

|

C．

a

⊥

b

⇒

a

•

b

=(

a

•

b

)2

D．

a

•

c

=

b

•

c

⇒

a

=

b