Answer
Domain: $x\leq 18$
Range: $y\leq 0$
Work Step by Step
The graph of the function begins at $x= 18$ and continues towards negative values of $x$, so $x\leq 18$.
The function's values start from zero and take on negative values as $x$ decreases towards negative, so $y\leq 0$.
Hence, the domain and range of the function are given by: \begin{equation}
\begin{aligned}
\textbf{Domain :}\quad & x\leq 18\\
\textbf{Range :}\quad & y\leq 0\\\\
\end{aligned}
\end{equation}
