Matrices Practice Questions Ques24

Question: Which of the following matrices is always symmetric?

Options:

(A) $A + A^T$

(B) $A - A^T$

(C) $A \cdot A^T$

(D) Option (A) and Option (C)

Show Answer

Answer: D

Explanation:

(A) Correct. $A + A^T$ is always symmetric because $(A + A^T)^T = A^T + (A^T)^T = A^T + A = A + A^T$.

(B) Incorrect. $A - A^T$ is skew-symmetric, not symmetric.

(C) Correct. $A A^T$ is always a symmetric matrix for any matrix A.

(D) Correct.