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Answer:
Step-by-step explanation:
Domain is from x to x.
You can use a ruler to determine it:
Put ruler perpendicular to X-axis at the left end. Move the ruler slowly along X-axis to the right.
When the ruler touch the graph there the x is the beginig of the domain.
Move along to the right. When the ruler touches end of graph there the x is end of the domain.
The filled dot means < >, and the empty dot means ( ).