Question

Decide whether the relation defined by the graph to the right, defines a function, and give the domain and range.

What is the domain and range?
Is it a defined function?

Answer 1

The relation in the graph is not a function

The domain is x ≥ -5

The range is all real numbers

What is a function

In mathematics, a function is a relation between a set of inputs (called the domain) and a set of possible outputs (called the codomain), such that each input is related to exactly one output.

A function assigns to each element in the domain a unique element in the codomain.

In the graph, for instance, we can see that x = 4 can have a value of both 2 and -4. This makes the relation not to be a function