KVPY2013MathematicsVector Algebra
Let v ₁, v₂ , v₃ , v₄ be unit vectors in the x y -plane, one each in the interior of the four quadrants. Which of the following statements is necessarily true?
Options
- Av₁ + v₂ + v₃ + v₄ =0
- BThere exist i , j with 1 i < j 4 such v_ i + v_ j is in the first quadrant
- CThere exist i , j with 1 i < j 4 such that v _ i v_ j < 0
- DThere exist i, j with 1 i 0
Correct answer
A. v₁ + v₂ + v₃ + v₄ =0
Step-by-step solution
In this case B, C, D are not possible.