Question

let the vector a and b be such that |a|=3 and |b|=√2/3 and a*b is a unit vector what is the angle between them?

Answer 1

Magnitude of the Vector product A × B = |A| * |B| * Sin θ.

So 3 × sqrt(2) /3 × Sin θ = 1.
Sinθ = 1/sqrt(2)

θ = 45°.