Two unit vectors A⃗ and B⃗ have a resultant A⃗+B⃗ that is also a unit vector. Find |A⃗-B⃗|.
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Question

Two unit vectors A⃗ and B⃗ have a resultant A⃗+B⃗ that is also a unit vector. Find |A⃗−B⃗|.

G1 Physics · Accepted Answer

|A+B|²=1 gives 1+1+2cosθ=1, so cosθ=−1/2. Then |A−B|²=2−2cosθ=3, hence |A−B|=√3.