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MHT CET202013 Oct 2020Morning ShiftMathematicsVector AlgebraActual

If the vectors a = -2 + k , b =2 -5 +p k and c =5 -9 +4 k are coplanar, then the value of p is

Options

  1. A-3
  2. B3
  3. C1 3
  4. D- 1 3

Correct answer

B. 3

Step-by-step solution

Given vectors are coplanar a ( b c )=0 aligned & | array rrr 1 & -2 & 1 2 & -5 & P 5 & -9 & 4 array |=0 & 1(-20+9 P )+2(8-5 P )+1(-18+25)=0 &-20+9 P +16-10 P +7=0 - P +3=0 P =3 aligned

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