2.1 Coordinate Plane.docx - The Coordinate Plane Chapter 2,...

The Coordinate Plane
Chapter 2, Section 1
Distance Formula in the Coordinate Plane
Let P = (x ₁ , y ₁ ) and Q = (x ₂ , y ₂ ) be any two points in the coordinate plane. Then the distance
between P and Q, denoted d(P, Q), is given by the distance formula
d ( P,Q )=
√
( x ₂ − x ₁ ) ² +( y ₂ − y ₁ ) ²
d ( P,Q )=
√
( x ₁ − x ₂ ) ² +( y ₁ − y ₂ ) ²
Example 1:
a) Find the distance between the points
(
4
√
5 , 5
)
∧(− 2
√
5 , − 9
b) Find the distance between the points on the graph.
)

Midpoint of a Line segment
The midpoint is halfway between the two endpoints.
 Its x value is halfway between the two x values