Lesson #17- Slope of a Line

Consider the roofs of 3 houses

Steep Steeper Steepest

=2

riserun

1

1

3

3riserun =

2

2

3

3riserun =

42

4=

21

We call the steepness of the line its SLOPE

The steeper the line the the slope.LARGER

Positive Slope Negative Slope

Up to the Right Down to the Right

eg. 1 Jacky’s Ride. Determine the slope.

S(-2,6)

F(2,0)

riserun

-64

=

=-32

= - 32

http://www.youtube.com/watch?v=IOsVsfqT7ls&feature=related

eg. 2 Balloon Rescue. Determine the slope.

H(-3,-2)

J(1,3)

riserun =

36

=12

It does not always make sense to draw a graph.In these cases you can use a _______ formula.shortcut

riserun =

y2-y1

x2-x1A(-4,3)

F(4,5)28

(x1,y1)

(x2,y2)

= (5) - (3)

(4) - (-4)

28

=

14=

Find the slope of the following:

riserun =

y2-y1

x2-x1

= (5) - (3)

(2) - (3)

2-1

=

21

= -

1) A(3,3) B(2,5) 2) C(-1,5) D(4,8)

riserun =

y2-y1

x2-x1

= (8) - (5)

(4) - (-1)

35

=

Homework

All problems on Slope of a Line Handout