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AP EAMCET202123 Aug 2021Morning ShiftMathematicsVector AlgebraActual

If 35 i +14 j -77 k , 2 i +7 j +5 k and 5 i +2 j + k are coplanar, then is equal to

Options

  1. A11
  2. B-11
  3. C-10
  4. D10

Correct answer

D. 10

Step-by-step solution

Given, 35 i +14 j -77 k , 2 i +7 j +5 k and 5 i +2 j + k are coplanar. Then, | array ccc 35 & 14 & -77 2 & 7 & 5 5 & 2 & array |=0 aligned & 35(7 -10)-14(2 -25)-77(4-35) & =0 & 203 +2233 & =0 & 203( +11) & =0 & & =-11 aligned

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