Solution
= Solution
The <symmetric part of a matrix> is
$$
\boxed{S=\frac12(A+A^{\mathsf T}).}
$$
It satisfies $S^{\mathsf T}=S$. The complementary term $(A-A^{\mathsf T})/2$ is a <skew-symmetric matrix>.
= Solution
The <symmetric part of a matrix> is
$$
\boxed{S=\frac12(A+A^{\mathsf T}).}
$$
It satisfies $S^{\mathsf T}=S$. The complementary term $(A-A^{\mathsf T})/2$ is a <skew-symmetric matrix>.