A rational parent function is the most basic rational function whose form is imitated by all other rational functions, and it is written as f(x) = 1 / x. Rational functions represent the division of two polynomials where the denominator must contain a variable.
The domain and range of a rational parent function is the set of all real numbers with the exception of 0. The graph of a rational function is a hyperbola. Excluded values are x-values that result in undefined y-values, hence they should be excluded from the domain. The parent rational function has the x- and y-axes as its asymptotes.