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Asked in NEET 2004 · Magnitude of the resultant
Given: |A⃗×B⃗|=√3(A⃗·B⃗).
Idea: first extract the angle from the condition, then feed it into the parallelogram law.
AB sin θ=√3 AB cos θ, so tan θ=√3 and θ=60°.
cos 60°=1/2.
|A⃗+B⃗|=√A²+B²+2AB cos θ=√A²+B²+2AB(1/2).
=(A²+B²+AB)^1/2.
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