Mathematics · 2021
JEE Main · 26 February 2021, Shift 1 · Q61
If a and b are perpendicular, then a ×( a ×( a ×( a × b ))) is equal to:
If $\displaystyle \vec{a}$ and $\displaystyle \vec{b}$ are perpendicular, then $\displaystyle \vec{a} \times(\vec{a} \times(\vec{a} \times(\vec{a} \times \vec{b})))$ is equal to:
Official answer
(3)
$\displaystyle |\overrightarrow{\mathrm{a}}|^4 \overrightarrow{\mathrm{~b}}$
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JEE Main 2021 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.