A weighted Euclidean inner product on $R^{2}$ is given for the vectors $\mathbf{u}=\left(u_{1}, u_{2}\right)$ and $\mathbf{v}=\left(v_{1}, v_{2}\right) .$ Find a matrix that generates it.
$$\langle\mathbf{u}, \mathbf{v}\rangle=3 u_{1} v_{1}+5 u_{2} v_{2}$$