Graphing Trigonometric Functions

This week’s topic is graphing trigonometric functions. When it comes to graphing, the internet provides a wealth of interactives and tutorials that can be utilized by students struggling with graphing. I want to start out by saying that I do not advocate students skipping paper and pencil methods of graphing, but I’m sure we have all noticed that some students have a very difficult time visualizing graphs. The websites I will provide this week should be used as supplemental materials.

When students learn the affects of amplitude, period, and phase shift on trigonometric functions they often have a hard time conceptualizing how changing one of these parameters affects the graph. I have watched students plug in numbers into an equation instead of analyzing the equation for changes. I want to provide you with interactives and graphing utilities that can help students easy change amplitude, period and phase shift to practice how these changes affect the graphs of trigonometric functions.

1. The GCalc graphing utility can easily graph trigonometric functions if students do not have graphing calculators. I recommend using this utility to have students quickly check their work and to analyze graphs for changes in amplitude, period, and phase shift.

2. The website from Illuminations at NCTM allows students to instantly change the amplitude, period, and phase shift to see the changes to sine, cosine, tangent, cosecant, secant, and cotangent functions.

3. The website from Analyze Math allows students to work on separate interactives for all the trigonometric functions. Scroll down to Trigonometric Functions and then choose an interactive.

4. The website at Interactive Mathematics provides students with a lesson on graphing sine, cosine, and tangent functions while providing an interactive for each of the lessons.

I hope that these websites and interactives will be helpful in your classroom and for your students.