Consider the following:

You have to evenly share your birthday cake between the friends that you invite to your birthday party. How would increasing the number of friends affect the size of each slice?

Clearly, an increase in the number of friends will result in a decrease in the size of each slice of cake.

This type of relationship is known as inverse variation. An increase in one variable results in a decrease in the other.

This relationship is seen in the graph below.

LESSON 1

LESSON 2