JEE Main 20265 Apr, Morning shiftMathematicsMediumVector Algebra184× since 2002Let a⃗=7i^+j^−k^\vec{a} = \sqrt{7}\hat{i} + \hat{j} - \hat{k}a=7i^+j^−k^ and b⃗=j^+2k^\vec{b} = \hat{j} + 2\hat{k}b=j^+2k^. If r⃗\vec{r}r is a vector such that r⃗×a⃗+a⃗×b⃗=0⃗\vec{r} \times \vec{a} + \vec{a} \times \vec{b} = \vec{0}r×a+a×b=0 and r⃗⋅a⃗=0\vec{r} \cdot \vec{a} = 0r⋅a=0, then ∣3r⃗∣2|3\vec{r}|^2∣3r∣2 is equal to:AOption A. 44BOption B. 54COption C. 86DOption D. 132CheckSkip · show solution
