Recognize Linear Relationships and Solve Equations with Technology

Using Geometer’s Sketchpad to Determine Rules from Graphs

iLearn Grade 7

Math Session 5 of 8

Focusing Questions

How do you determine the symbolic rule from a graph?

How does Geometer’s Sketchpad support determining rules from graphs?

Instruction

Framing The Session

You will gain experience in linking symbolic and graphical representations of linear relationships. Symbolic rules will be given in more than one form and you will be asked to rewrite it in standard form.

Teaching

“I know you have been working on graphing patterns and connecting multiple representations of linear relationships. Now we will use GSP to match rules to graphs.”

“Find page 351-353, Investigation 3: From Rules to Graphs, Think & Discuss, Problems Set F, and Share & Summarize. Then find a partner.”

Guided Practice

Read the table (page 351) that summarizes the relationships between the structure of a pattern, the numbers in the corresponding rules, and the features of the corresponding graph.

Work Time

Getting Started

Find Problem Set F on page 352 in IMPACT Math. With your partner decide who will be first to draw a graph (Graph Maker) and who will look for clues (Detective) in the graph to decide which rule was used.”

c will equal y, and d will equal x when using GSP.

Work TimeGraph Maker – in GSP go to:

File/New Sketch

Graph/Grid Form/Square Grid

Graph/New Function/Equation/y = f(x)

Select a rule from the list below and input it in the New Function window. Press OK. Go to:

Graph/Plot Function

Select Function. Go to:

Display/Hide Function

Show the graph to the Detective.

Work TimeDetective – Look for clues in the graph to decide

which rule is used. You may ask the Graph Maker to label coordinate points and drag the origin to move the graph in order to get a better view. Show your choice of equation to the Graph Maker who will confirm your choice. If the Detective is correct the Graph Maker will go to:

Display / Show All Hidden

Partners exchange roles and repeat steps.

Share

Participants will create a graph and the group will use clues to decide what equation is represented by the graph.

Participants will create charts from the equations in the Share & Summarize, create graphs using the charts and use the results to answer questions

Share

If applicable, use this area to record comments and feedback captured during the share.

Share

How does this work address how Geometer’s Sketchpad supports determining rules from graphs?

Answers

For more information

Office of Instructional Technology

oittc@schools.nyc.gov

www.nyc.gov/schools