MHT CET202012 Oct 2020Morning ShiftMathematicsVector AlgebraActual

The value of m , if the vectors - -6 k , -3 +4 k and 2 -5 +m k are coplanar, is

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Correct answer

C. 3

Step-by-step solution

a = i - j -6 k , b = i -3 j +4 k , c =2 i -5 j +m k are coplanar aligned & | array rrr 1 & -1 & -6 1 & -3 & 4 2 & -5 & ~m array |=0 & 1(-3 ~m +20)+1( ~m -8)-6(-5+6)=0 &-3 ~m +20+ m -8+30-36=0 -2 ~m +6=0 m =3 aligned

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