| Matrix | 
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 An array of numbers is called a matrix.  | 
 
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Figure 1. | 
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Here, we have some data organized in a table. It could be rewritten in a matrix:
 
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Figure 2. | 
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Matrices are usually described by their dimensions.
 
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Figure 3. | 
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Each entry in a matrix is called an element.
 
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Figure 4. | 
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Here are three examples of matrices with different dimensions:
 
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Figure 5. | 
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