Question
The angle made by the vector $A = \hat i + \hat j$ with $x-$ axis is ....... $^o$
✓
Answer
(b) $\vec A = \hat i + \hat j$
$⇒$ $|A| = \sqrt {{1^2} + {1^2}} = \sqrt 2 $
$\cos \alpha = \frac{{{A_x}}}{{|A|}} = \frac{1}{{\sqrt 2 }} = \cos 45^\circ $
$⇒$ $\alpha = 45^\circ $
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