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AP EAMCET201825 Apr 2018Morning ShiftMathematicsVector AlgebraActual

If a → , b → , c → are unit vectors and the maximum value of | a → - b → | 2 + | b → - c → | 2 + | c → - a → | 2 is k , then k 2 a → 2 + 3 b → 2 - 4 c → 2 =

Options

  1. A6
  2. B8
  3. C9
  4. D12

Correct answer

C. 9

Step-by-step solution

Given, a → ,   b →   &   c → are unit vectors. Therefore a → = b → = c → = 1 Now, we have | a → - b → | 2 + | b → - c → | 2 + | c → - a → | 2 = a → 2 + b → 2 - 2 a → · b → + b → 2 + c → 2 - 2 b → · c → + c → 2 + a → 2 - 2 c → · a → = 6 - 2 a → · b → + b → · c → + c → · a →     &#1

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