In order to see an application of sinusoidal curves that has relevance to themselves students will compute their biorhythm information, find the sinusoidal function that fits the information and graph them on the graphing calculator. They will use this information to compute future "good" and "bad" days.

Students will have studied the basic trigonometric functions and their transformation properties. They will use the textbook and the attached worksheet as additional review. The worksheet will be done without a calculator and then checked using the calculator.

The students will be given the attached worksheet and two class periods to complete the work. It will take one day for calculations and one day for graphing in a 45 minute period. All work will be checked with teacher initials at critical points.

The student will produce a graph paper copy of their biorhythm with all included calculations that matches the graphing calculator picture. They will extend their graph to cover the next month and also submit predictions of their future "bad" and "good" days for the upcoming month. The teacher will check the calculations and then graph the sinusoidal functions to make sure they are accurate. After one month, the class will review the predicted information and compare it to the collected information to determine the accuracy of the predictions.