A matrix which is both symmetric as well as skew-symmetric is a null matrix.

Explanation

To show that a matrix which is both symmetric and skew-symmetric is a null matrix, we can follow these steps:

### Step 1: Define the Matrix
Let \( A \) be a square matrix. We denote its elements as follows:
\[
A = \begin{pmatrix}
a_{11} & a_{12} & a_{13} \\
a_{21} & a_{22} & a_{23} \\
...