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MHT CET202019 Oct 2020Evening ShiftMathematicsVector AlgebraActual

If a =3 + - k , b =2 - +7 k and c =7 - +23 k are three vectors, then which of the following statement is true.

Options

  1. Aa , b and c are non-coplanar.
  2. Ba , b and c are coplanar.
  3. Ca , b , c are mutually perpendicular.
  4. Da and b are collinear.

Correct answer

A. a , b and c are non-coplanar.

Step-by-step solution

(C) a =3 i + j - k , b =2 i - j +7 k , c =7 i - j +23 k aligned [ array ccc a & b & c array ] &= | array ccc 3 & 1 & -1 2 & -1 & 7 7 & -1 & 23 array | &=3(-23+7)-1(46-49)-1(-2+7) &=3(-16)-(-3)-(5)=-50 0 aligned a , b , c are non coplanar.

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