Functions defined on intervals
Trips and reflections (I)

The dynamic figure below contains:
  • A story about a bike ride, during which the rider decreased her speed.
  • A sketch of a graph describing the story.
  • A table containing quantitative information that can be gleaned from the story.

    The figure also includes three other stories, which can be described in graphs by performing horizontal or vertical reflections on parts of the initial graph. The axes of reflection pass through the point representing the time and position at which the rider of the first story decreased her speed.


  • position
    time
    f
    g
    speed end
    position
    end
    time
    start
    position
    start
    time
    f
    g


    How are the quantities specified in story 1 expressed in the graph?
  • Use reflections to construct graphs that fit stories 2,3, and 4. Record the sketch that corresponds to each story.
  • Examine the sketches you constructed and describe the changes that occurred in the endpoints of the intervals making up the graph and in the slopes of these intervals. Record the data in the table that appears in the tool.
  • Use the Representing motion at several speeds tool to check whether you can construct a precise description of each story with the data you have and answer the questions that appear in the story. Can answers to questions in one story help you find answers to questions in the other stories?


  • to part II






    Piecewise linear functions

    Journeys at two speeds
    Planning a trip
    Stories about journeys
    Trips and reflections
    Overtime
    Coupons
    Mobile phone rates
    Income Tax (I)
    Income Tax (II)