MCQ
If $|\overrightarrow A \times \overrightarrow B |\, = \,|\overrightarrow A \,.\,\overrightarrow B |,$ then angle between $\overrightarrow A $ and $\overrightarrow B $ will be ........ $^o$
- A$30$
- ✓$45$
- C$60$
- D$90$
✓
Answer
Correct option: B.
$45$
b
(b) $|\vec A \times \vec B|\, = \vec A.\vec B$
(b) $|\vec A \times \vec B|\, = \vec A.\vec B$
$⇒$ $AB\sin \theta = AB\cos \theta $
$⇒$ $\tan \theta = 1$
$\theta = 45^\circ $
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