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MHT CET202124 Sep 2021Morning ShiftMathematicsThree Dimensional GeometryActual

If a =2 i - j + k , b = i +2 j -3 k and c =3 i + j +5 k are coplanar, then is the root of the equation

Options

  1. Ax^2+3 x=6
  2. Bx^2+2 x=4
  3. Cx^2+3 x=4
  4. Dx^2+2 x=6

Correct answer

C. x^2+3 x=4

Step-by-step solution

Since given vectors are coplanar, we write aligned & | array ccc 2 & -1 & 1 1 & 2 & -3 3 & & 5 array |=0 & 2(10+3 )+1(5+9)+1( -6)=0 & 20+6 +14+ -6=0 7 +28=0 =-4 aligned Which is one of the root of equation in option C

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