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@@ -56,21 +56,15 @@ $
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\vec{a} \cdot \vec{b} =
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(^{x_a} _{y_a})
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\cdot
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-(^{x_b} _{y_b})
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-= x_a*x_b + y_a*y_b
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+(^{x_b} _{y_b}) = x_a*x_b + y_a*y_b
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$
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- 3D：
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-
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-$
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-\vec{a} \cdot \vec{b} =
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-\begin{pmatrix}
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-x_a \\ y_a \\ z_a\
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-end{pmatrix}
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+$\vec{a} \cdot \vec{b} =
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+\begin{pmatrix} x_a \\ y_a \\ z_a\end{pmatrix}
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\cdot
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\begin{pmatrix} x_b \\ y_b \\ y_c \end{pmatrix}
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-= x_a * x_b + y_a * y_b + z_a * z_b
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-$
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+= x_a * x_b + y_a * y_b + z_a * z_b $
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