Education Technology

String Graphs Part1

Activity Overview

This is part one of a four part series. In this activity students use the gradient and intercept form of a straight line to form a curved envelope similar to that found on the Chords bridge. In the second half of this activity students learn to use a parameter so that the family of graphs can be generated using a single equation.


Students determine the equation to a straight line given the y intercept and information about the gradient. Students find patterns in the series of straight lines in order to generate a single equation for the family of straight lines. Specific calculator techniques are also covered in the activity.


  • Gradient
  • Rise / Run
  • Y-Intercept
  • Parameter
  • Independent Variable
  • Dependent Variable
  • Family of linear functions

About the Lesson

Watch Activity Tutorial

Part One of a Four Part Series. In this activity students determine the equation to a family of straight lines given the y intercept and gradient (by calculation). Students then generate the family of straight lines by developing a general formula and corresponding parameter. A full series of videos are available for students to watch to assist with completing the activity or activity series.