If the volume of the porallelopiped with \(\bar{a} \times \vec{b}, \vec{b} \times \vec{c}\) and \(\vec{c} \times \vec{a}\) on coterminous edges is \(9 \mathrm{cu}\). Unit, then the volume of the parallelepiped with \((\vec{a} \times \vec{b}) \times(\vec{b} \times \vec{c})\). \((\vec{b} \times \vec{c}) \times(\vec{c} \times \vec{a})\) and \((\vec{c} \times \vec{a}) \times(\vec{a} \times \vec{b})\) on conterievinans edges is :
If the volume of the parallelepiped with `a x b`, `b x c`, and `c x a` on coterminous edges is 9 cu. Unit, then the volume of the parallelepiped with `(a x b) x (b x c)`, `(b x c) x (c x a)`, and `(c x a) x (a x b)` on conterievinans edges is :
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Let’s denote the vectors as \(\vec{a}, \vec{b}, \) and \(\vec{c}\).
Volume of the First Parallelepiped
The volume of the parallelepiped formed by vectors \(\vec{a} \times \vec{b}, \vec{b} \times \vec{c},\) and \(\vec{c} \times \vec{a}\) can be expressed as the scalar triple product of these vectors:
\[
\text{Volume} = [(\vec{a} \times \vec{b}) \cdot ((\vec{b} \times \vec{c}) \times (\vec{c} \times \vec{a}))]
\]
Using the vector triple product identity, \(\vec{A} \times (\vec{B} \times \vec{C}) = \vec{B}(\vec{A} \cdot \vec{C}) – \vec{C}(\vec{A} \cdot \vec{B})\), we can simplify the expression:
\[
\text{Volume} = [(\vec{a} \times \vec{b}) \cdot (\vec{b}(\vec{b} \cdot \vec{a}) – \vec{a}(\vec{b} \cdot \vec{b}))]
\]
Expanding further:
\[
\text{Volume} = [(\vec{a} \times \vec{b}) \cdot \vec{b}(\vec{b} \cdot \vec{a})] – [(\vec{a} \times \vec{b}) \cdot \vec{a}(\vec{b} \cdot \vec{b})]
\]
Since \((\vec{a} \times \vec{b}) \cdot \vec{b} = 0\) and \((\vec{a} \times \vec{b}) \cdot \vec{a} = 0\) (as the cross product is perpendicular to both vectors), the volume of the first parallelepiped is 0.
Volume of the Second Parallelepiped
For the second parallelepiped, we have the vectors \((\vec{a} \times \vec{b}) \times(\vec{b} \times \vec{c})\), \((\vec{b} \times \vec{c}) \times(\vec{c} \times \vec{a})\), and \((\vec{c} \times \vec{a}) \times(\vec{a} \times \vec{b})\). The volume can be similarly expressed as the scalar triple product:
\[
\text{Volume} = [((\vec{a} \times \vec{b}) \times(\vec{b} \times \vec{c})) \cdot (((\vec{b} \times \vec{c}) \times(\vec{c} \times \vec{a})) \times ((\vec{c} \times \vec{a}) \times(\vec{a} \times \vec{b})))]
\]
Using the same vector triple product identity and the fact that the cross product of any two vectors is perpendicular to both, we can deduce that the volume of the second parallelepiped is also 0.
In summary, the volume of the second parallelepiped with \((\vec{a} \times \vec{b}) \times(\vec{b} \times \vec{c})\), \((\vec{b} \times \vec{c}) \times(\vec{c} \times \vec{a})\), and \((\vec{c} \times \vec{a}) \times(\vec{a} \times \vec{b})\) on coterminal edges is \(0 \, \mathrm{cu. \, units}\).