Gaokao Math Practice Question
3. (5 分) 设向量 $\vec{a}, \vec{b}$ 满足 $|\vec{a}+\vec{b}|=\sqrt{10},|\vec{a}-\vec{b}|=\sqrt{6}$, 则 $\vec{a} \bullet \vec{b}=(\quad)$
- A.1
- B.2
- C.3
- D.5
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