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AP EAMCET202123 Aug 2021Evening ShiftMathematicsVector AlgebraActual

Let A = i +2 j . If B is a vector in X Y plane such that ( A + B ) B =15 and A B =6 , then | B | is

Options

  1. A6
  2. B9
  3. C15
  4. D3

Correct answer

D. 3

Step-by-step solution

A = i +2 j Let B =x i +y j ( A + B ) B =15 and A B =6 A B + B B =15 array cc & 6+| B |^2=15 & | B |^2=15-6=9 & | B |=3 array

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