###### Example4.8.6

Let's plot the line with equation $$y=3\text{.}$$ (Note that this is the same as $$0x+1y=3\text{.}$$)

To plot some points, it doesn't matter what $$x$$-values we use. All that matters is that $$y$$ is always $$3\text{.}$$

A line like this is horizontal, parallel to the horizontal axis. All lines with an eqaution in the form

\begin{equation*} y=k \end{equation*}

(or, in standard form, $$0x+By=C$$) are horizontal.

in-context