ICT resources for maths teachers

7. Advanced graphs

In this workshop we will continue exploring graphs by looking at trignometric identities.

The value of graphs in spreadsheets is that, once you have drawn the graph, you can change values and observe the changes taking place in the graph. This makes spreadsheets a good learning tool. In the course on Developing classroom resources for maths you will design a lesson integrating ICT in this way. As you learn more about graphs, start to consider ways in which you could use graphs in Microsoft Excel to teach mathematical principles.

Follow these steps to complete this activity. While practicing with Microsoft Excel, look for contexts that are meaningful to you in your classroom and create documents that you can adapt and use at a later stage. We will make suggestions about what documents to create, but if you prefer, you may create documents to suit your own needs.

Work in pairs (45 min)

Trignometric graphs

• The graphs of the three trigonometric ratios, sine, cosine and tangent can easily be plotted using Microsoft Excel.

  1. Open the Excel workbook and follow the example for sinA.
  2. Calculate the values for sin2A and 2sinA
  3. Draw all three identities on one chart.

   

Click here to open the example workbook (save the file and then open it in Microsoft Excel)

How to draw charts

Work in pairs (45 min)

Challenge

• Create a sample of graphs that graphically prove the following trigonometric identities or any other identity.
  
  
  sin ( A + B ) = sin A cos B + cos A sin B
  and
  sin 2 A = ½ (1 - cos 2A )

Meet in groups or as a class (30 min)

• Discuss your work by displaying and sharing your solutions with your colleagues.
• Create a list of other graphs that you could draw and manipulate with Microsoft Excel.

Work on your own (between workshops)

• Plan some worksheets using graphs and think about how you would construct them in Equation Editor. Next time you have the opportunity, create these worksheets using Microsoft Word's Equation Editor.

You have the option of using the South African National Portal (Thutong) to enhance this workshop activity.