[a b a b] is equal to - Vidyadip

MCQ

$[\bar{a} \bar{b} \bar{a} \times \bar{b}]$ is equal to

A
$|\bar{a} \times \bar{b}|$
✓
$|\overline{ a } \times \overline{ b }|^2$
C
$\overline{0}$
D
None of these

✓

Answer

Correct option: B.

$|\overline{ a } \times \overline{ b }|^2$

(B) $\left[\begin{array}{lll}\overline{ a } & \overline{ b } & \overline{ a } \times \overline{ b }\end{array}\right]=\overline{ a } \cdot[\overline{ b } \times(\overline{ a } \times \overline{ b })]$
$=(\overline{ a } \times \overline{ b }) \cdot(\overline{ a } \times \overline{ b })$
$=|\overline{ a } \times \overline{ b }|^2$

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