JEE Main202124 Feb 2021Evening ShiftMathematicsDeterminantsActual
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 A 2 B 2 - B 2 A 2 X = O , where X is a 3 × 1 column matrix of unknown variables and O is a 3 × 1 null matrix, has
Options
- Aexactly two solutions
- Binfinitely many solutions
- Ca unique solution
- Dno solution
Correct answer
B. infinitely many solutions
Step-by-step solution
Let A T = A and B T = - B C = A 2 B 2 - B 2 A 2 C T = A 2   B 2 T - B 2   A 2 T = B 2 T A 2 T - A 2 T B 2 T = B 2   A 2 - A 2   B 2 C T = - C C is skew symmetric. So det C = 0 so system have infinite solutions.