Chapter 8

      Rational Functions

      A rational function is special in that the function rule involves a fraction with a polynomial in both the numerator and the denominator. Rational functions have restrictions in their domain; any value creating a 0 in the denominator has to be excluded. Many of these exclusions are identified as vertical asymptotes. The x-intercepts of rational functions can be solved for by setting the numerator equal to 0; this is done after you’ve determined that there are no common factors in the numerator and denominator. A rational function can have a horizontal asymptote — as long as the highest power in the numerator is not greater than that in the denominator.

The Problems You’ll Work On

      In this chapter, you’ll work with rational functions in the following ways:

What to Watch Out For

      Don’t let common mistakes trip you up; watch out for the following ones when working with rational functions:

Investigating the Domain of a Rational Function

       411–420 Determine the domain of the rational function.

      411.

      412.

      413.

      414.

      415.

      416.

      417.

      418.

      419.

      420.

Determining a Function’s Removable Discontinuity

       421–430 Find the removable discontinuity of the function.

      421.

      422.

      423.

424.

      425.

      426.

      427.