jee-main 2018 Q87

jee-main · India · 15apr Vectors Introduction & 2D Dot Product Computation

If $\vec { a } , \vec { b } , \vec { c }$ are unit vectors such that $\vec { a } + 2 \vec { b } + 2 \vec { c } = \overrightarrow { 0 }$, then $| \vec { a } \times \vec { c } |$ is equal to :
(1) $\frac { 1 } { 4 }$
(2) $\frac { 15 } { 16 }$
(3) $\frac { \sqrt { 15 } } { 4 }$
(4) $\frac { \sqrt { 15 } } { 16 }$

If $\vec { a } , \vec { b } , \vec { c }$ are unit vectors such that $\vec { a } + 2 \vec { b } + 2 \vec { c } = \overrightarrow { 0 }$, then $| \vec { a } \times \vec { c } |$ is equal to :\\
(1) $\frac { 1 } { 4 }$\\
(2) $\frac { 15 } { 16 }$\\
(3) $\frac { \sqrt { 15 } } { 4 }$\\
(4) $\frac { \sqrt { 15 } } { 16 }$

Paper Questions

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