Let y1 be a function that takes an input x (the length of a line segment) and outputs the segment's length as described by Problem C1. Write a formula for y1.
If x is the input, describing a rule to determine the output will help you find the formula. Close Tip
Problem C6
Let y2 be a function that takes an input x (the length of a line segment) and outputs the segment's length as described by Problem C2. Write a formula for y2.
Graph the functions you created in Problems C5 and C6. Describe any similarities or differences in the graphs.
One way to make these graphs is to create a table of values for each function, then plot and connect the points on each graph. Close Tip
A relationship is proportional if the ratio of inputs and outputs is the same for all inputs and outputs. This kind of relationship is also sometimes referred to as direct variation.
Problem C8
Look at the graphs you created in Problems C5 and C6. Use the graphs to decide whether or not either function represents a proportional relationship.
Video Segment In this video segment, the onscreen participants compare the graphs in Problem C7 and use the graphs to explain their observations about quadperson. Watch this segment after you have completed Problems C5-C8 and compare your observations about the graphs with those of the onscreen participants.
Would the graphs of two different proportional relationships intersect? Where?
You can find this segment on the session video, approximately 14 minutes and 34 seconds after the Annenberg Media logo.
