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Q.
The vector $\vec{ a } \times (\vec{ b } \times \vec{ c }$ ) is:
Vector Algebra
Solution:
Consider $\vec{ a } \times(\vec w{ b } \times \vec{ c })=(\vec{ a \cdot c }] \vec{ b }+(\vec{ a } \cdot \vec w{ b }) \vec{ c }$
$\Rightarrow \bar{a} \times(\bar{b} \times \bar{c})$ lie in the plane of $\bar{ b }$ and $\bar{c}$ which is parallel to $\vec{ a }$.