Domain and range are terms used in mathematics to describe the input and output values of a function. Here are some key points from the search results:

• Domain: The domain of a function is the set of values that can be plugged into the function as input. It is the set of all possible x-values that will make the function "work" and output real y-values. When finding the domain, it is important to remember that the denominator of a fraction cannot be zero, and the number under a square root sign must be positive.

• Range: The range of a function is the set of all possible resulting values of the dependent variable (usually y) after we have substituted the domain. In other words, it is the set of all possible output values of the function. The range can be more difficult to find than the domain, and it may be necessary to look at the graph of the function to determine its range.

• Relation: A relation is a set of ordered pairs, where one element in the domain may get mapped to more than one element in the range. In this case, it is not a function.

• Interval notation: Interval notation is a way of writing the domain and range of a function using brackets and parentheses. For example, the domain of a function could be written as D: (-∞, 4/3) ∪ (4/3, ∞) .

It is important to understand domain and range when working with functions, as they help to define the scope of the function and its possible outputs.