Let the vectors a⃗ and b⃗ be such that |a⃗| = 3 and |b⃗| = /3, then a⃗ × b⃗ is a unit vector, if the angle between a⃗ and b⃗ is
Explanation
For the cross product vector a⃗ × b⃗ to be a unit vector, its magnitude must equal 1. The magnitude of a cross product is given by |a⃗ × b⃗| = |a⃗| |b⃗| sin θ, where θ is the angle between the two vectors. Given |a⃗| = 3 and |b⃗| = /3, we set up the equation: 3 × (/3) × sin θ = 1, which simplifies to × sin θ = 1, giving sin θ = 1/. Since sin(π/4) = 1/, the angle between the vectors must be π/4.
Solution Steps
Step 1: For a⃗ × b⃗ to be a unit vector, |a⃗ × b⃗| = 1
Step 2: Using the formula |a⃗ × b⃗| = |a⃗| |b⃗| sin θ
Step 3: Substitute given values: 3 × (/3) × sin θ = 1
Step 4: Simplify: × sin θ = 1
Step 5: Solve: sin θ = 1/
Step 6: Therefore, θ = π/4 (since sin π/4 = 1/)