Question
The volume of the parallelepiped whose sides are given by $$\overrightarrow {OA} = 2i - 2j,\,\,\overrightarrow {OB} = i + j - k,\,\,\overrightarrow {OC} = 3i - k,$$ is :
A.
$$\frac{4}{{13}}$$
B.
$$4$$
C.
$$\frac{2}{7}$$
D.
none of these
Answer :
none of these
Solution :
Volume of parallelepiped $$ = \left[ {\vec a\,\vec b\,\vec c} \right]$$
\[ = \left| \begin{array}{l}
2\,\,\, - 2\,\,\,\,\,0\\
1\,\,\,\,\,\,1\,\,\, - 1\\
3\,\,\,\,\,0\,\,\, - 1
\end{array} \right| = 2\left( { - 1} \right) + 2\left( { - 1 + 3} \right) = 2\]