Activity Overview
In this TI InterActive!™ activity, students study the phases of the moon, plot the fraction of the moon showing each day in a month, and fit the data with an appropriate trigonometric function.
Before the Activity
Install the TI InterActive!™ on the computer
Print the page from the attached file for the class
During the Activity
Distribute the printed page to the class.
Follow the Activity procedures:
Identify the eight recognized stages in the lunar cycle
Use the Internet to find the approximate period of the moon's cycle
Determine the fraction of the moon showing for the days of the year
Set up a scatter plot of the fraction of the Moon showing in January versus the day of the year
Observe the graph and determine the amplitude and the vertical translation
Find a cosine and a sine function which fits the data
Identify the phase shift for the function
Repeat the steps for the fraction of moon showing in January and February
After the Activity
Students answer questions on the activity page.
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary