Let $\phi$ be a D2864: Real gaussian density function with parameters $\mu \in \mathbb{R}$ and $\sigma^2 \in (0, \infty)$.

Then

(1)	$\phi$ is a D1416: Differentiable euclidean real function on $\mathbb{R}$
(2)	\begin{equation} \phi' (x) = - \frac{x - \mu}{\sigma^2} \phi(x) \end{equation}