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Question
Write the value of \[\left[ 2 \hat { i } \ 3 \hat { j }\ 4 \hat { k } \right] .\]
Solution
We have
\[\left[ 2\hat { i} \ 3\hat {j} \ 4 \hat {k} \right]\]
\[ = \left( 2\hat { i} \times 3 \hat {j} \right) \cdot 4 \hat {k} \left( \because \left[ \vec{a} \vec{b} \vec{c} \right] = \left( \vec{a} \times \vec{b} \right) . \vec{c} \right)\]
\[ = 6 \hat {k} \cdot 4 \hat {k} \]
\[ = 24\]
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