How to Find the Domain of a Graph

The domain is all the possible x-values shown on a graph.

Move your eyes from left to right to see where the graph exists.

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Check where the graph begins on the x-axis.

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Notice where the graph stops on the x-axis.

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If the graph has breaks, those x-values are not part of the domain.

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Open circles mean the value is not included, closed circles mean it is included.

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Use interval notation or set notation to clearly show the domain.

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How to Find the Domain of a Graph

The domain is all the possible x-values shown on a graph.

Understand What Domain Means

Move your eyes from left to right to see where the graph exists.

Look at the Graph Horizontally

Check where the graph begins on the x-axis.

Find the Starting Point

Notice where the graph stops on the x-axis.

Find the Ending Point

If the graph has breaks, those x-values are not part of the domain.

Check for Gaps or Breaks

Open circles mean the value is not included, closed circles mean it is included.

Watch for Open and Closed Circles

Use interval notation or set notation to clearly show the domain.

Write the Domain Correctly