# What is the domain of x=-4?

$\left\{- 4\right\}$
The equation $x = - 4$ defines a relation, not a function, since any point $\left(- 4 , y\right)$ is in its graph.
The only value of $x$ for which the relation contains a point is $- 4$. So the domain is $\left\{- 4\right\}$ and the range is $\mathbb{R}$