Answer
Domain = $(-\infty,\infty)$
Range: $(-\infty,12]$
Work Step by Step
The arrows on either side of the curve indicate that x can take any value.
Domain = $(-\infty,\infty)$
The function values peak at y=12 (included),
For the values that are less, they are not bounded in the negative side...
Range: $(-\infty,12]$