Let $ A, B $ be matrices of order $ n $, and $ \vec{u}, \vec{v} $ vectors from euclidean space $ \mathbb{R}^n $, then $ (Au,Bv) = (u,A^tBv) $
pd. $(\cdot ,\cdot)$ is my notation for inner product, and $ A^t $ is the transpose of $A$
I don't know how to demonstrate that, and I'm not sure if it's true.
There's my demo, I can't complete it. Maybe I'm not using the right definitions,
