The domain is the horizontal extent of the function. This function is defined for all values of x greater than (but not including) -4. Its domain is (-4, ∞).
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The range is the vertical extent of the function. This function gives output values of any number greater than or equal to -4. Its range is [-4, ∞).
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Interval notation uses square brackets when the value is included in the interval. It uses round brackets (parentheses) when the end value is not included in the interval. ∞ is not a number, so that end always gets a round bracket.
