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Q.The angle between the vectors (a⃗+b⃗)(\vec{a} + \vec{b}) and (a⃗−b⃗)(\vec{a} - \vec{b}) if ∣a⃗∣=∣b⃗∣=a|\vec{a}| = |\vec{b}| = a is

a
cos⁡−1(a⃗⋅b⃗a2)\cos^{-1} (\dfrac{\vec{a} \cdot \vec{b}}{a^2})
b
2cos⁡−1(a⃗⋅b⃗a2)2 \cos^{-1} (\dfrac{\vec{a} \cdot \vec{b}}{a^2})
c
cos⁡−1(−a⃗⋅b⃗a2)\cos^{-1} (\dfrac{ - \vec{a} \cdot \vec{b}}{a^2})
d
90∘90^\circ

Correct Answer: Option B

The correct solution involves applying the fundamental concept to derive the final value step by step...

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