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AP EAMCET2006MathematicsVector Algebra

If a + b + c = 0 and | a |=3,| b |=4 and | c |= 37 , then the angle between a and b is :

Options

  1. A4
  2. B2
  3. C6
  4. D3

Correct answer

D. 3

Step-by-step solution

a + b + c =0 a + b =- c ( a + b )^2=(- c )^2 | a |^2+| b |^2+2| a || b | =| c |^2 9+16+2 3 4 =37 24 =37-25 = 1 2 = 3 = 3

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