Domain and Range
Domain
The domain of a function is the set of values of the independent variable (x) for which the function is defined.
There are two common mathematical operations that are undefined: square root of a negative number and division by zero.
Because a square root cannot successfully act on a negative number, the domain of
is all real numbers x such that 
. In set notation, this would be written 
.
Division by zero is undefined; therefore values for x that produce a zero denominator are excluded from the domain. For instance, the function
has a domain of all real numbers except 
and 
. In set notation, this would be written 
.
There are two common mathematical operations that are undefined: square root of a negative number and division by zero.
Because a square root cannot successfully act on a negative number, the domain of
is all real numbers x such that . In set notation, this would be written .Division by zero is undefined; therefore values for x that produce a zero denominator are excluded from the domain. For instance, the function
has a domain of all real numbers except and . In set notation, this would be written .