Explanation
Solution
To find the correct option, we need to look at the definitions of symmetric and skew-symmetric matrices.
1. Definition of a Symmetric Matrix:
A square matrix A is symmetric if it is equal to its transpose:
2. Definition of a Skew-Symmetric Matrix:
A square matrix A is skew-symmetric if it is equal to the negative of its transpose:
3. Combining the two conditions:
Since the problem states that A is both symmetric and skew-symmetric, we can set the two expressions for AT equal to each other:
4. Solving for A:
Add A to both sides of the equation:
Where O represents the zero matrix (a matrix where every element is zero).
Final Answer:
The correct option is (b) A is zero matrix.