ExamBro
ExamBro
CUET · MATHS · PYQ PAPER 2025

If A and B are symmetric matrices of the same order, then which of the following are true?
(A) AB - BA is a skew symmetric matrix
(B) AB is a symmetric matrix
(C) AB is a scalar matrix
(D) AB + BA is a symmetric matrix
Choose the correct answer from the options given below:

  1. A (A), (B) and (C) only
  2. B (A) and (D) only
  3. C (C) and (D) only
  4. D (B), (C) and (D) only
Verified Solution

Answer & Solution

Correct Answer

(B) (A) and (D) only

Step-by-step Solution

Detailed explanation

Given \( A^T = A \) and \( B^T = B \). For (A): \( (AB - BA)^T = (AB)^T - (BA)^T \) \( = B^T A^T - A^T B^T \) \( = BA - AB \) \( = -(AB - BA) \) Thus, (A) is true. For (D): \( (AB + BA)^T = (AB)^T + (BA)^T \) \( = B^T A^T + A^T B^T \) \( = BA + AB \) \( = AB + BA \) Thus, (D) is…