The domain is how far left-to-right the graph goes. (It’s identifying the x-values used by the graph.)
This graph starts at -11 on the left and then goes all the way to 10 on the right, but it doesn’t actually get to 10, because of the open circle.
So -11 ≤ x < 10 is the domain.
In interval notation, that’s [-11,10).
In set-builder notation, that’s { x | -11 ≤ x < 10 }.
