JEE Main202120 Jul 2021Morning ShiftPhysicsMathematics in PhysicsActual
If A → and B → are two vectors satisfying the relation A → · B → = | A → × B → | . Then the value of | A → - B → | will be:
Options
- AA 2 + B 2
- BA 2 + B 2 + 2 A B
- CA 2 + B 2 + 2 A B
- DA 2 + B 2 - 2 A B
Correct answer
D. A 2 + B 2 - 2 A B
Step-by-step solution
A → · B → = | A → × B → | A B cosθ = A B sinθ ⇒ θ = 45 ° | A → - B → | = A 2 + B 2 - 2 A B cos 45 ° = A 2 + B 2 - 2 A B Hence option ( 4 ) .