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AP EAMCET2004MathematicsVector Algebra

If the vectors i +3 j +4 k , i -4 j + k are orthogonal to each other, then is equal to

Options

  1. A5
  2. B-5
  3. C8
  4. D-8

Correct answer

C. 8

Step-by-step solution

Let a = i +3 j +4 k and b = i -4 j + k Since, a and b are orthogonal to each other array lc & a b =0 & ( i +3 j +4 k ) ( i +4 j + k )=0 & -12+4=0 =8 array

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