Question in image. :)

Answer:
All real numbers greater than or equal to 0.
General Formulas and Concepts:
Algebra I
Step-by-step explanation:
According to the graph, we see that our x-values span from 0 to infinity. Since 0 is a closed dot, it is inclusive in the domain:
[0, ∞) or x ≥ 0 or All Real Numbers greater than or equal to 0.