1. Drill 10-11/13
Copy the data then
Find the mean
4, 6, 7, 9, 12, 15, 23, 30, 30
Put Both HW on the corner of
your desk.
You do not need your book
today

2. Objective
•SWBAT determine
the slope of a line
given two points
and graph an
equation given the
slope and a point.

3. Slope
• We have seen slope in a
couple of different ways
at this point:
• Change in y over
change in x:
• Or:
x
y
run
rise

4. SLOPE EQUATION
If you are given two points of the
form:
(x1 , y1) and (x2 , y2)
The slope of the line containing
those points is:
12
12
xx
yy
m

5. Examples
• Determine the slope of the
line containing the points
(-3 , 5) and (4 , -2)
m =

6. Examples
• Determine the slope of the
line containing the points
(2 , -4) and (3 , -6)
m =

7. Special Cases
• If the slope of a line is
equal to zero then the line
is horizontal.
• (2, -7) and (5, -7)
m =

8. Special Cases
• If the slope of a line is undefined
(can’t divide by zero) then the
line is vertical.
• (-3, 4) and (-3, -2)
m =

9. Now moving along…
• We will now use the slope
of an equation to graph.
• Remember slope is:
run
rise

10. Using Slope to Move on a Graph
•We can move
from one point to
another on a
graph by using the
slope written as a
fraction. (if it is not
a fraction we can
make it one!)

11. Using Slope to Move on a Graph
• Now we can think of it this way:
• If the top number is positive,
move up! If it is negative, move
down.
• The bottom number is always
positive so we move right!
rightmovefar toHow
downorupmovefar toHow

13. Slope
• We have seen slope in a
couple of different ways
at this point:
• Change in y over
change in x:
• Or:

14. SLOPE EQUATION
If you are given two points of the
form:
(x1 , y1) and (x2 , y2)
The slope of the line containing
those points is:
12
12
xx
yy
m

15. Examples
• Determine the slope of the
line containing the points
(-3 , 5) and (4 , -2)
m =

16. Examples
• Determine the slope of the
line containing the points
(2 , -4) and (3 , -6)
m =

17. Special Cases
• If the slope of a line is
equal to zero then the line
is horizontal.
• (2, -7) and (5, -7)
m =

18. Special Cases
• If the slope of a line is undefined
(can’t divide by zero) then the
line is vertical.
• (-3, 4) and (-3, -2)
m =

19. Study Guide #’s 1 – 9
1. For each problem, label x1,
y1, x2, and y2.
2. Write the slope equation un-
simplified.
3. Simplify the top and bottom.
4. Simplify the fraction if
necessary

20. Determining a point…
• Sometimes you will be given
the slope of a line and three
of the 4 values.
• If this happened just set up
your equation and solve for
the unknown.

21. Example 1
• Given the slope and the information
about the points determine the
missing coordinate:
• (10, r) and (3, 4); m = -2/7

22. Example 2
• Given the slope and the information
about the points determine the
missing coordinate:
• (4, 8) and (r, 2); m = 2

23. Now moving along…
• We will now use the slope
of an equation to graph.
• Remember slope is:
run
rise

24. Using Slope to Move on a Graph
• Now we can think of it this way:
• If the top number is positive,
move up! If it is negative, move
down.
• The bottom number is always
postitive so we move right!
rightmovefar toHow
downorupmovefar toHow