Question

If `veca` and `vecb` are unit vectors, then what is the angle between `veca` and `vecb` for `sqrt(3)  veca - vecb` to be a unit vector?

Options

• 30°

• 45°

• 60°

• 90°

Answer 1

30°

Explanation:

We have `(sqrt(3)  veca - vecb)^2 = 3veca^2 + vecb^2 - 2sqrt(3)  veca*vecb`

`\implies veca * vecb = sqrt(3)/2`

`\implies` cos θ = `sqrt(3)/2`

`\implies` θ = 30°