Do Now 5/18/11
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Take out HW from last night.
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Copy HW in your planner.
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Punchline worksheets #115 & 116.
Text p. 479, #8-18 evens, 19-22 all, 28-32 evens & 44
Quiz sections 9.3 & 9.5 Friday
In your journal, find the following regarding points on
a coordinate plane.



What is the distance between the two points (2, 3) & (2, 7)?
What is the distance between the two points (2, 3) & (-5, 3)?
What is the distance between the two points (2, 7) & (-5, 3)?
Homework
Punchline worksheets 115 & 116
Did You Hear About…
THE MATH STUDENT WHO WALKED
AROUND A CITY BLOCK BY TAKING A
SQUARE ROUTE?
Where Does the Scent of a Lady’s Perfume Go?
NO ONE NOSE
Coordinate Plane
y-axis
Quadrant II
(-,+)
Origin
(0,0)
Quadrant I
(+,+)
x-axis
Quadrant III
(-,-)
Quadrant IV
(+,-)
Plotting Points
ordered
pair
(2,4)
y-axis
(-3,4)
5
C
4
A
3
(2,-3)
2
1
-6
-5
x-axis
-4
-3 -2 -1
0
1
2
3
-1
-2
(-6,-4)
-3
D
-4
-5
B
4
5
6
Describe the Location of Each Point.
y-axis
5
Quadrant 2
Quadrant 1
4
3
C
2
x-axis
A
1
-6
-5 F -4
-3 -2 -1
0
x-axis
Quadrant 3
D
1
2
3
4
5
6
-1
Quadrant 4
-2
E
-3
-4
-5
B
y-axis
Objective

SWBAT find the distance between two
points

SWBAT find the midpoint of a line
segment
What is the distance between points A and B?
y-axis
(-3,4)
(2,4)
5
4
A
C
3
2
7 units
1
-6
-5
x-axis
-4
-3 -2 -1
0
1
2
3
4
5
-1
-2
-3
-4
-5
B
(2,-3)
6
What is the distance between points C and A?
5 units
y-axis
(-3,4)
(2,4)
5
4
A
C
3
2
1
-6
-5
x-axis
-4
-3 -2 -1
0
1
2
3
4
5
-1
-2
-3
-4
-5
B
(2,-3)
6
What is the distance between points C and B?
y-axis
(-3,4)
(2,4)
5
4
A
C
3
2
1
-6
-5
x-axis
-4
-3 -2 -1
0
1
2
3
4
5
-1
-2
-3
-4
-5
B
(2,-3)
6
Section 9.5 “The Distance and
Midpoint Formulas”
Distance Formula
y
To find the distance
between two points
( x2 , y2 )
( x1 , y1 )and( x2 , y2 )
( x1 , y1 )
x
d  ( x2  x1 )  ( y2  y1 )
2
2
Find the distance between (6,3) and (5,7)
Let( x1 , y1 )  (6,3)
Let( x2 , y2 )  (5,7)
d  ( x2  x1 ) 2  ( y2  y1 ) 2
d  (5  6)  (7  3)
2
d  ( 1) 2  ( 4) 2
d  1 16
d  17
d  4.1
2
Find the distance between (-1,3) and (5,2)
Let( x1 , y1 )  (1,3)
Let( x2 , y2 )  (5,2)
d  ( x2  x1 ) 2  ( y2  y1 ) 2
d  (5  (1))  (2  3)
2
d  (6) 2  ( 1) 2
d  36 1
d  37
d  6.1
2
Section 9.5 “The Distance and
Midpoint Formulas”
y
Midpoint Formula
The midpoint (middle point) between
two points can be found by:
 x1  x2 y1  y2 
,


2 
 2
( x2 , y2 )
( x1 , y1 )
x
Find the midpoint of a line segment
with endpoints (-1,-2) and (3,-4)
Let( x1 , y1 )  (1,2)
Let( x2 , y2 )  (3,4)
 x1  x2 y1  y2 
,


2 
 2
  1  3  2  (4) 
,


2
 2

2 6
 ,

2 2 
1,3
Find the midpoint of a line segment
with endpoints (6,-3) and (4,-7)
Let( x1 , y1 )  (6,3)
Let( x2 , y2 )  (4,7)
 x1  x2 y1  y2 
,


2 
 2
 6  4  3  (7) 
,


2
 2

 10  10 
 ,

2 2 
5,5
Homework
Text p. 479, #8-18 evens, 19-22 all, 28-32 evens & 44