Aim #7.1: What is the difference between direct and inverse variation?The equation y =ax represents direct variation between x and y. Y is said to vary directly with x. The constant a is called the constant of variation.

Example 1: Classifying Equations

Extra Example 1:

Check for Understanding 1:

Direct vs. Inverse

– Direct variation:– A set of ordered pairs (x, y)

show direct variation when the ratios are constant.

– Inverse Variation:– For inverse the equation y=

can be rewritten as xy=a.– So when the products of the

ordered pairs xy=a is constant then the data is an

example of inverse variation.

Example 2: Is it direct or Inverse?

Extra Example 2:

Check for Understanding 2:

Example 3: Writing Inverse Variation Equations

Extra Example 3:

Check for Understanding 3:

Summary: Answer in complete

sentences.– What does the equation of direct variation look like? and inverse variation?– What does a represent?Given a table of data points- how do you determine if its inverse or direct variation?

HOMEWORK: Text p. 363 prob 3 - 24