1.7 Midpoint and Distance in the Coordinate Plane 9/22/10 You can use formulas to find the midpoint...
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Transcript of 1.7 Midpoint and Distance in the Coordinate Plane 9/22/10 You can use formulas to find the midpoint...
1.7 Midpoint and Distance in the Coordinate Plane 9/22/10
• You can use formulas to find the midpoint and the length of any segment in the coordinate plane.
Number Line Coordinate Plane
2
a bM
1 2 1 2,2 2
x x y yM
Finding the Midpoint• Segment AB has endpoints at -4 and 9. What
is the coordinate of its midpoint?
2
a bM
4 9
2M
5
2M 2.5
Finding the Midpoint• Segment EF has endpoints E (7 , 5) and
F (2 , -4). What are the coordinates of its midpoint M?
1 2 1 2,2 2
x x y yM
7 2 5 ( 4)
,2 2
M
9 1,2 2
M
(4.5,0.5)M
Finding an Endpoint• The midpoint of segment CD is M(-2 , 1). One
endpoint is C (-5 , 7). What are the coordinates if the other endpoint D?
2 25 7( 2,1) ,
2 2
x y 25
22
x
24 5 x
21 x
271
2
y
22 7 y
25 y (1, 5)D
Distance Formula• The distance between two points A(x1 , y1) and
B(x1 , y1) is2 2
2 1 2 1( ) ( ) .d x x y y
Finding Distance• What is the distance between U(-7 , 5) and
V(4 , -3)? Round to the nearest tenth?
2 22 1 2 1( ) ( )d x x y y
2 2(4 ( 7)) ( 3 5)d
2 2(11) ( 8)d
121 64
185 13.6
More Practice!!!!!
• Classwork – Textbook p. 54 #7 – 29 odd.
• Homework – Textbook p. 54 #6 – 30 even.