Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Advanced2021MathematicsMatricesActual

For any 3 × 3 matrix M , let | M | denote the determinant of M . Let E = 1 2 3 2 3 4 8 13 18 , P = 1 0 0 0 0 1 0 1 0 & F = 1 3 2 8 18 13 2 4 3 If Q is a nonsingular matrix of order 3 × 3 , then which of the following statements is (are) TRUE ?

Options

  1. AF = P E P and P 2 = 1 0 0 0 1 0 0 0 1
  2. BE Q + P F Q - 1 = | E Q | + P F Q - 1
  3. C( E F ) 3 > | E F | 2
  4. DSum of the diagonal entries of P - 1 E P + F is equal to the sum of diagonal entries of E + P - 1 F P

Correct answer

A. F = P E P and P 2 = 1 0 0 0 1 0 0 0 1

Step-by-step solution

(1) P 2 = 1 0 0 0 0 1 0 1 0 1 0 0 0 0 1 0 1 0 = 1 0 0 0 1 0 0 0 1 = I PEP = 1 0 0 0 0 1 0 1 0 1 2 3 2 3 4 8 13 18 1 0 0 0 0 1 0 1 0 = 1 2 3 8 13 18 2 3 4 1 0 0 0 0 1 0 1 0 = 1 3 2 8 18 13 2 4 3 = F (2) Here, F = P E P ⇒ P F = P 2 E P ⇒ P F = E P , E = 0 ,   F = 0 E Q + P F Q - 1 = E Q + E P Q - 1 = ∣ E Q + P Q - 1 | = | E | | Q + P Q - 1 ∣ = 0 | E Q | + P F Q - 1 = 0 + 0 = 0 (3) Since, | E | = 0 ⇒ | E F | = 0 Thus, E F 3 > E F 2 is not possible (4) P = 1 0 0 0 0 1 0 1 0 &#8658

Practice Matrices on Quantrex Academy →

More from Matrices

Which one of the following matrices can be obtained by performing elementary row transformations on the 3 3 identity matrix? 2026Consider the matrix M = bmatrix 2 & -1 1 & 0 bmatrix . Let p, q, r, s, a, b, c and d be integers such that M²⁶ = bmatrix p & q r & s bmatrix and _ k=1 ²⁶ M^k = bmatrix a & b c & d 2026For real numbers , , , and , consider the matrix M = bmatrix & 1 2 & - 1 2 1 3 & & 1 3 & & bmatrix . Suppose that MM^T = I , where M^T is the transpose of the matrix M , and I is t 2026Let R denote the set of all real numbers and let i = -1 . Consider the matrices S = bmatrix 0 & -1 1 & 0 bmatrix and T = bmatrix 1 & 1 0 & 1 bmatrix . Let a, b, c, d be real number 2026Let A = bmatrix & 1 & 2 2 & 3 & 0 0 & 4 & 5 bmatrix and B = bmatrix 1 & 0 & 0 0 & -5 & 0 0 & 4 & -2 bmatrix + adj (A) . If (B)=66 , then ( adj (A)) equals: 2026Let A = bmatrix 1 & 0 & 0 3 & 1 & 0 9 & 3 & 1 bmatrix and B = [b_ ij ] , 1 i, j 3 . If B = A⁹⁹ - I , then the value of b₃₁ - b₂₁ b₃₂ is : 2026Let A = bmatrix -1 & 1 & -1 1 & 0 & 1 0 & 0 & 1 bmatrix satisfy A^2 + (adj(adj(A))) + (adj(A)(adj(adj(A)))) = bmatrix 2 & -2 & 2 -2 & 0 & -1 0 & 0 & -1 bmatrix for some , R . Then 2026Let M be a 3 3 matrix such that M pmatrix 1 0 0 pmatrix = pmatrix 1 2 3 pmatrix , M pmatrix 0 1 0 pmatrix = pmatrix 0 1 2 pmatrix and M pmatrix 0 0 1 pmatrix = pmatrix -1 1 1 pmatr 2026 Full Matrices list All JEE Advanced PYQs