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KCET2019MathematicsThree Dimensional Geometry

A unit vector perpendicular to the plane containing the vectors ( i +2 j + k ) and ( -2 i + j +3 k ) is

Options

  1. A( i + j - k 3 )
  2. B( - i - j - k 3 )
  3. C( i + j + k 3 )
  4. D(- i + j - k )

Correct answer

D. (- i + j - k )

Step-by-step solution

(D) [ array l n = ( a b | a b | ) a b = | array rrr i & j & k 1 & 2 & 1 -2 & 1 & 3 array |=5 i -5 j +5 k | a b |=5 3 n = i - j + k 3 or n = - i + j - k 3 array ]

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