A) 18
B) 16
C) 10
D) 8
Correct Answer: B
Solution :
We have \[\left| \begin{matrix} \vec{a}.\vec{a} & \vec{a}.\vec{b} & \vec{a}.\vec{c} \\ \vec{a}.\vec{b} & \vec{b}.\vec{b} & \vec{b}.\vec{c} \\ \vec{a}.\vec{c} & \vec{b}.\vec{c} & \vec{c}.\vec{c} \\ \end{matrix} \right|={{[\vec{a}\,\,\vec{b}\,\,\vec{c}]}^{2}}\] \[={{\left| \begin{matrix} 1 & 1 & 1 \\ 1 & -1 & 1 \\ 1 & 2 & -1 \\ \end{matrix} \right|}^{2}}=16\]You need to login to perform this action.
You will be redirected in
3 sec