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MHT CET202210 Aug 2022Morning ShiftMathematicsVector AlgebraActual

If a , b , c are unit vectors such that a + b + c = 0 , then the value of a b + b c + c a is

Options

  1. A0
  2. B-1 2
  3. C2
  4. D-3 2

Correct answer

D. -3 2

Step-by-step solution

aligned & | a + b + c |=| a |^2+| b |^2+| c |^2+2( a b + b c + c a ) & 0=1^2+1^2+1^2+2( a b + b c + c a ) & a b + b c + c a =- 3 2 aligned

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