The graph provided represents a quadratic function, and you are asked to determine the function's domain.

A quadratic function, such as the one shown here, typically has a domain that includes all real numbers. This is because quadratic functions are defined for every value of $x$.

In this case, the graph is a parabola, and since it extends infinitely in both the left and right directions along the $x$-axis, the domain is all real numbers.

Thus, the domain of the function is:

$(-\infty, \infty)$

Would you like further explanation or help with another aspect of the problem?

Here are some related questions:

1. How can you find the vertex of a quadratic function from its graph?
2. What does the "range" of a quadratic function refer to?
3. How can the coefficients of the quadratic function $f(x) = ax^2 + bx + c$ affect the graph?
4. What is the axis of symmetry in a quadratic function's graph?
5. How do you solve quadratic equations using the quadratic formula?

Tip: When identifying the domain and range of a function, always observe whether the function has any restrictions or if it extends infinitely in any direction.