Finding The Slope of a Line

The slope we are studying is associated with the graph of a line.

Definitions of Slope The tilt or inclination of a line The ratio of vertical change to horizontal change. The change in y over the change in x Allow students time to copy May need to review that a ratio is a comparison of numbers

Tilt or Inclination Discuss positive and negative slope. Discuss when slope equals 0 and is undefined.

Vertical Change Horizontal Change This ratio is also known as Rise Run

Example 1: Plot your points Remember to click to make each part appear

Draw a line through the points. Line will appear automatically

Now that we have our line lets find its slope. Remember we are finding the following ratio: Vertical or Rise Horizontal Run

Vertical Change or the Rise 3 Discuss vertical change

Horizontal Change or the Run 4 3 Discuss horizontal change

Vertical Rise Horizontal Run 3 4 May need to remind students that a ratio is a comparison of two numbers

Example 2: Find the Slope

The slope is… 1 2

Example 3: Find the Slope

The slope is…. -3 Discuss why the slope is negative and that –3/1 reduces to –3.

Find the slope of these lines. Have students practice.

The slope is… Black line 3 Red Line 1 Blue Line -1/2

Find the slope of this line

The slope is… Orange line 0

Practice Time!