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MHT CET202123 Sep 2021Morning ShiftMathematicsVector AlgebraActual

If | a |=4,| b |=5 , then the values of k for which a +k b is perpendicular to a -k b are

Options

  1. A5 4
  2. B2 5
  3. C16 25
  4. D4 5

Correct answer

D. 4 5

Step-by-step solution

aligned & ( a +k b ) ( a -k b )=0 & |a|^2-k^2|b|^2=0 & (4)^2-k^2(5)^2=0 k= 4 5 aligned

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