Domain and Range
Range
The range of a function is the set of values of the dependent variable, y, for which the function is defined.
To illustrate range, consider the function 
. The domain of this function is all real numbers x such that 
; in other words, the input can be any number greater than or equal to –7.
What output does this function produce? Consider the following table of values:
Note as the x values increase, the y values also increase. However, the input 
is undefined. Hence, the range of this function is all real numbers y such that 
. In set notation, this would be written 
.