Two vectors A and B have equal magnitudes. If magnitude of A+ B is equal to two times the magnitude of A− B, then the angle between A and B will be :

Question

Accepted Answer

Correct answer: C. (c) (a^2 + b^2 + 2ab cosθ) = 4 (a^2 + b^2 -2ab cosθ) put a = b we get 2a^2 + 2a^2 cosθ = 8a^2 - 8a^2 cosθ c o s θ= 35

$Two vectors A and B have equal magnitudes. If magnitude of A + B is equal to two times the magnitude of A - B, then the angle between A and B will be :$