Question

If theta is the angle between unit vectors A bar and B bar,then 1-A.B by 1 A.B is equals to

Answer 1

We have, |a|2=1,|b|2=1,|3–√b−a|2=1

Let, a→⋅b→=cosθ i.e. angle between them is θ

|3–√b−a|2=1

(3–√|b|)2+|a|2−23–√b→⋅a→=1

3|b|2+|a|2−23–√cosθ=1

3+1−23–√cosθ=1

3=23–√cosθ

cosθ=323√

cosθ=3√2

θ=30∘