In my linear algebra class, my professor gave us an exercise, which is the following.
If A is an nxn matrix over the complex, one can show that A = ST for S and T both invertible and symmetric.
I guess I can use Jordan Block, but I don't know the exact step.
Can someone help me?
Every Jordan block can be factorized into two symmetric matrices, 3 by 3 for instance. $$ \pmatrix{ &&\lambda \\ & \lambda &\\ \lambda&& } \cdot \pmatrix{ &&1\\ &1 &1\\ 1&1& } $$
Now use the fact that conjugation of a symmetric matrix is still symmetric.
Moreover, if $A$ is nonsingular, then so are $S$ and $T$.