The Coordinate Plane

A coordinate plane is formed by two number lines that intersect at right angles. The point of intersection is the ZERO on each number line – it is called the origin.

  • The two number lines are called the axes.
  • The horizontal axis is called the x-axis.
  • The vertical axis is called the y-axis.

The two axes divide the coordinate plane into four quadrants.

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To give the location of a point on a coordinate plane, you need to use TWO numbers, called an “ordered pair”. The first number tells how far to move right (positive) or left (negative) from the origin. The second number tells how far to move up (positive) or down (negative) from the x-axis.

The numbers in an ordered pair are called coordinates. The first number is called the x-coordinate and the second number is called the y-coordinate. The coordinates for the origin in (0, 0).

Drag Point A around the plane. Notice as the coordinates change. Also notice the quadrant you are in.

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Duane Habecker, 03/14/2010, Created with GeoGebra

 

 

DIRECTIONS:

Move Point A to the indicated point.

Click the blue arrows for a new point to plot.

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Duane Habecker, 03/14/2010, Created with GeoGebra

 

 


 

Self-Check


Question 1

Which point is located at (2, 5)?

sc1

 

[show answer]


Question 2

Which point is located at (-3, 2)?

sc2

 

[show answer]


Question 3

Which point is located at (1, -2)?

sc3

 

[show answer]