A function from a set to a set is a relation that assigns to each element in the set exactly one element in the set . The set is the domain (also called the set of inputs) of the function and the set contains the range (also called the set of outputs).
The graph of a function is the collection of ordered pairs such that is in the domain of being:
the directed distance from the .
the directed distance from the .
By plotting the function we get the graph illustrated below.
From this graph, we know that:
The vertex is the maximum value
The function is positive for no values of x
The function is decreasing when
The domain of the function is all real numbers
The range of the function is all real numbers less or equal to 0