Symmetric Matrices & Quadratic Forms · Easy problem

The quadratic form $q(\mathbf x) = \mathbf x^{T}B\mathbf x$ is written with the non-symmetric matrix $B = \begin{pmatrix}1 & 4\\0 & 3\end{pmatrix}$. Let $A$ be the symmetric matrix with $\mathbf x^{T}A\mathbf x = q(\mathbf x)$ for all $\mathbf x$. Find the entry of $A$ in row 1, column 2.