Question

If the sum of the two unit vectors is also a unit vector, then magnitude of their difference is 

1. √ 2
2. √ 3
3. √ 4
4. √ 7

Answer 1

Correct Answer 2. √3

Explanation :

  a = b, b = 1.

 If Angle between a and b is 'θ '.

 r² = a² + b² + 2ab cos θ 

= 1 = 1 + 1 + 2 cos θ 

= cos θ = - 1/2

 To find