x
y
(x,y)
x - coordinate
y - coordinate
How are coordinates helpful?
A coordinate plane is composed
of a horizontal number line (x-axis) and a vertical number line (y-axis).
(-- , +)
(+ , +)
(-- , --) (+ , --)
y
x
The point where
the two axes intersect is the
origin.
origin
(-- , +)
(+ , +)
(-- , --) (+ , --)
y
x
origin
(-- , +)
(+ , +)
(-- , --) (+ , --)
An ordered pair is a pair of numbers used to name a location on a grid.
y
x
The first number, or the x-coordinate, tells how far to the right or left the point is located in the horizontal direction(x-axis).
(3 , 2)x
y
x
The second number, or the y-coordinate, tells how far up or down the point is located in the vertical direction (y-axis). The coordinates of the origin are (0 , 0)
(3 , 2)y
y
x
The coordinate axes divide the plane
into four regions called quadrants.
QuadrantQuadrant
Quadrant Quadrant
(+ , +)(-- , +)
(-- , --) (+ , --)
y
x
All points in Quadrant I have two positive coordinates.
Quadrant I
(+ , +)
y
x
Quadrant II
(-- , +)
All coordinates in Quadrant II have a negative x-coordinate and a positivey-coordinate
y
x
Quadrant III
(-- , --)
All coordinates in Quadrant III have a negative x-coordinate and a negativey-coordinate.
y
x
Quadrant IV
(+ , --)
All coordinates in Quadrant IV have a positive x-coordinate and a negativey-coordinate.
y
x
Ordered Ordered PairsPairs
Ordered Pairs – are used to locate points on a grid.
The number that is used to represent a point are called coordinates. (2 , 4) are the coordinates on point P.
0 1 2 3 4 5 6 7 8 9 10 11
1
2
3
4
5
6
7
8
9
10
11