Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202619 April 2026Morning ShiftMathematicsVector AlgebraActual

The value of x so that the volume of the parallelopiped formed by the vectors i + x j + k , j + x k and x i + k is minimum, is

Options

  1. A-3
  2. B3
  3. C1 3
  4. D3

Correct answer

C. 1 3

Step-by-step solution

The volume of the parallelopiped formed by the vectors a , b , and c is given by the absolute value of their scalar triple product, V = |[ a , b , c ]| . Given vectors: a = i + x j + k b = 0 i + j + x k c = x i + 0 j + k Calculating the scalar triple product: [ a , b , c ] = vmatrix 1 & x & 1 0 & 1 & x x & 0 & 1 vmatrix Expanding the determinant along the first row: = 1(1 1 - x 0) - x(0 1 - x x) + 1(0 0 - 1 x) = 1(1) - x(-x^2) + 1(-x) = x^3 - x + 1 So, the volume is V = |x^3 - x + 1| . Let f(x) = x^3 - x + 1 . To f

Practice Vector Algebra on Quantrex Academy →

More from Vector Algebra

P is the circumcentre of A B C . If the position vectors of A, B, C and P are a , b , c , a + b + c 4 respectively, then the position vector of the orthocentre of this triangle is 2025If the position vectors of A, B, C, D are i +2 j +2 k , 2 i - j , i + j +3 k and 4 j +5 k respectively, then the quadrilateral ABCD is a 2025The set of all real values of c so that the angle between the vectors a = cx i -6 j +3 k and b =x i +2 j +2 cx k is an obtuse angle for all real x is 2025Let a =2 i + j +3 k , b =3 i +3 j + k and c = i -2 j +3 k be three vectors. If r is a vector such that r a = r b and r c =18 , then the magnitude of the orthogonal projection of 4 2025If u , v , w are non coplanar vectors and p, q are real numbers, then the equality [ array lll 3 u & p v & p w array ]- [ array lll p v & w & q u array ]- [ array lll 2 w & q v & q 2025Let i -2 j + k , i + j -2 k , 2 i - j - k and i + j + k be the position vectors of four points A , B , C and D respectively. If a point P divides AB in the ratio 2: 1 internally an 2025If a = i + j , b =2 j - k are two vectors such that r a = b a , r b = a b , then the unit vector in the direction of r is 2025If a , b , c are three unit vectors such that a ( b c )= 3 2 b + c 2 and , are the angles between a , c and a , b respectively, then + = 2025 Full Vector Algebra list All MHT CET PYQs