Given that A + B = Cand that C is to A. F

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Given that $\overrightarrow A + \overrightarrow B = \overrightarrow C $and that $\overrightarrow C $ is $ \bot $ to $\overrightarrow A $. Further if $|\overrightarrow A |\, = \,|\overrightarrow C |,$then what is the angle between $\overrightarrow A $ and $\overrightarrow B $

A

$\frac{\pi }{4}radian$

B

$\frac{\pi }{2}radian$

C

$\frac{{3\pi }}{4}radian$

D

$\pi \,\,radian$

Given that $\overrightarrow A + \overrightarrow B = \overrightarrow C $and that $\overrightarrow C $ is $ \bot $ to $\overrightarrow A $. Further if $|\overrightarrow A |\, = \,|\overrightarrow C |,$then what is the angle between $\overrightarrow A $ and $\overrightarrow B $

Given, $A+B=C$

and $B=C-A$

Since, $C \perp A$, therefore

$B^{2}=C^{2}+A^{2}$

Also, $|C|=|A|,$ therefore

$B^{2}=2 A^{2} \Rightarrow B=\sqrt{2} A$

$\mathrm{Now}, A^{2}+B^{2}+2 A B \cos \theta=C^{2}=A^{2}$

$\therefore \cos \theta=\frac{1}{\sqrt{2}}$

This gives $\theta=\frac{3 \pi}{4}$ rad