Example 1

A cell-phone plan charges customers a monthly fee, which includes minutes of talk time. After talk minutes, the customer is charged a minute. The total monthly charges, , for any number of talk minutes, , can be represented using the piecewise function . Create a graph to show the monthly charges for any number of talk minutes.
  1. Determine the domain and range of the first piece of the function.
  2. Find at least two points on the graph of the first piece of the function.
  3. Use the two points to graph the first piece of the function.
  4. Determine the domain and range for the second piece of the function.
  5. Find at least two points on the graph of the second piece of the function.
  6. Use the two points to graph the second piece of the function.
This applet is provided by Walch Education as supplemental material for their mathematics programs. Visit www.walch.com for more information on their resources.