1. Finding the Slope of a Line
Fill in the notes on your handout as we go through the lesson today!!

2. What You’ll Learn
To find the slope of a line and use it to solve problems.

3. Why learn about slope?

4. What is slope?
Slope is a ratio that describes the steepness of a line. It compares the vertical change in a line, called the rise, to the horizontal change, called the run.
Using any 2 points on a straight line will compute to the same slope.
We use the letter m to stand for a line’s slope.

6. Example 1: Finding the Slope of a Line When Given 2 Points
You can find the slope of a line when given two points by using the formula
m = y2 – y1 when using the ordered pair (x1,y1)
x2 – x1 and (x2,y2)
Why do we use the difference in y divided by the difference in x to find slope? Since we are looking at the difference in y and x, slope is sometimes called the rate of change.

7. Finding the Slope of a Line When Given 2 Points

8. Finding the Slope of a Line When Given 2 Points – Your Turn!
Find the slope of the line that goes through points (4,8) and (5,10)
Find the slope of the line in the picture below.

9. Find the slope of a line using a table.

10. Example 2 – Finding a Point on a Line
You can also find a point on a line when given the slope and a point on the line.
The slope of a line is 2/3. One point on the line is (0,2). Find another point on the line. We will use:
-The slope of a line is 2. One point on the line is (3,4). Find another point on the line.
-The slope of a line is 3/5. One point on the line is (3,1). Find another point on the line.
m = y2 – y1
x2 – x1

11. Example 2 – Your Turn!
The slope of a line is 2/5. One point on the line is (2,4). Find another point on the line.
The slope of a line is -1/2. One point on the line is (2,0). Find another point on the line.

12. Slope
The slope of a line can be positive, negative, zero or undefined. Why?
This is a graph of y = ?
The slope is undefined. Why?
This is a graph of x = ?

13. Example 3: Drawing Lines on a Graph

14. Drawing Lines on a Graph – Your Turn!
Draw a line through P(2,1) with a slope of 4/3.