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MHT CET202015 Oct 2020Evening ShiftMathematicsVector AlgebraActual

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

Options

  1. Ax²+2 x=6
  2. Bx²+2 x=4
  3. Cx²+3 x=6
  4. Dx²+3 x=4

Correct answer

D. x²+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 Put x=-4 in all options. (A) 8-12=-4 6 (B) 16-8=8 4 (C) 16-12=4 (D) 16-8=8 6

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