By the end of this lesson, you accomplished several goals:

• Vary variables. You dragged independent points and observed and described the behavior of dependent point(s).
• Distinguish independent and dependent variables. You learned how to tell the difference between independent and dependent variables.
• Distinguish functions and non-functions. You used the drag test to tell the difference between functions and non-functions.
• Define “function.” You formulated and discussed your own definition of function.
• Apply your definition. You used your definition to categorize relations as functions or not functions.
• Use the term “relation.” You became familiar with the term relation to describe variables with a relationship that may or may not be a function.