HARD
JEE Main
IMPORTANT
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Let M be any 3×3 matrix with entries from the set 0,1,2. The maximum number of such matrices, for which the sum of diagonal elements of MTM is seven, is______.

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Important Questions on Matrices and Determinants

HARD
JEE Main
IMPORTANT

For the system of linear equations:

x-2y=1, x-y+kz=-2, ky+4z=6, kR

Consider the following statements:
(A) The system has unique solution if k2,k-2.
(B) The system has unique solution if k=-2.
(C) The system has unique solution if k=2.
(D) The system has no-solution if k=2.
(E) The system has infinite number of solutions if k-2. 

Which of the following statements are correct?

HARD
JEE Main
IMPORTANT
Let A and B be 3×3 real matrices such that A is a symmetric matrix and B is a skew-symmetric matrix. Then the system of linear equations A2 B2-B2 A2X=O, where X is a 3×1 column matrix of unknown variables and O is a 3×1 null matrix, has
MEDIUM
JEE Main
IMPORTANT
If A=0-tanθ2tanθ20 and I2+AI2-A-1=a-bba, then 13a2+b2 is equal to _____ .
MEDIUM
JEE Main
IMPORTANT
Let A=xyzyzxzxy, where x, y and z are real numbers such that x+y+z>0 and xyz=2. If A2=I3, then the value of x3+y3+z3 is
EASY
JEE Main
IMPORTANT
If the system of equations

kx+y+2z=1

3x-y-2z=2

-2x-2y-4z=3

has infinitely many solutions, then k is equal to ______ .

HARD
JEE Main
IMPORTANT
Let A be a 3×3 matrix with detA=4. Let Ri denote the ith row of A. If a matrix B is obtained by performing the operation R22R2+5R3 on 2 A, then detB is equal to :
MEDIUM
JEE Main
IMPORTANT
If for the matrix, A=1-ααβ, AAT=I2, then the value of α4+β4 is :
HARD
JEE Main
IMPORTANT
The following system of linear equations
2x+3y+2z=9
3x+2y+2z=9
x-y+4z=8