JEE Mains · Physics · STD 11 - Vectors
- JEE Mains 2022
- Medium
- MCQ
Two vectors \(\overrightarrow{ A }\) and \(\overrightarrow{ B }\) have equal magnitudes. If magnitude of \(\overrightarrow{ A }+\overrightarrow{ B }\) is equal to two times the magnitude of \(\overrightarrow{ A }-\overrightarrow{ B }\), then the angle between \(\overrightarrow{ A }\) and \(\overrightarrow{ B }\) will be .......................
Pick an option to check your answer.
Answer & Solution
Correct Answer
(C) \(\cos ^{-1}\left(\frac{3}{5}\right)\)
Step-by-step Solution
Detailed explanation
\(\left(a^{2}+b^{2}+2 a b \cos \theta\right)=4\left(a^{2}+b^{2}-2 a b \cos \theta\right)\)
put \(a\) = \(b\) we get
\(2 a^{2}+2 a^{2} \cos \theta=8 a^{2}-8 a^{2} \cos \theta\)
\(\cos \theta=\frac{3}{5}\)
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