Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main20258 Apr 2025Evening ShiftMathematicsMatricesActual

Let be a solution of x^2+x+1=0 , and for some a and b in R , [ array lll 4 & a & b array ] [ array ccc 1 & 16 & 13 -1 & -1 & 2 -2 & -14 & -8 array ]= [ array ccc 0 & 0 & 0 array ] . If 4 ^4 + m ^ a + n ^ b =3 , then m + n is equal to

Options

  1. A3
  2. B11
  3. C7
  4. D8

Correct answer

B. 11

Step-by-step solution

x^2+x+1=0 is root aligned & ^2+ +1=0 & = as ^2 [cube root of unity] aligned also . array l [ array ll 4-a-2 b & 64-a-14 b array 52+2 a-8 b . array ] aligned & = [ array ll 0 & 0&0 array ] & a+2 b=4 & a+14 b=64 & 12 b=60 b=5 & a=-6 & 4 ^4 + m ⁻⁶ + n ^5 =3 & 4 + m 1 + n ^2 =3 & 4 ^2+m+n =3 aligned aligned & 4 (- 1 2 - 3 2 i )+ m + n (- 1 2 + 3 2 i )=3 & -2+ m - n 2 =3....(1) & & -4 3 2 + n 3 2 =0 & n =4 & ~m =7 & ~m + n =11 aligned

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 Main PYQs