9-3 The Coordinate Plane

Learn to locate and graph points on the coordinate plane.

9-3 The Coordinate Plane

Vocabularycoordinate planeaxesx-axisy-axisquadrantsorigincoordinatesx-coordinatey-coordinate

9-3 The Coordinate Plane

A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line.

• The two number lines are called the axes.

9-3 The Coordinate Plane

A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line.

• The horizontal axis is called the x-axis.

9-3 The Coordinate Plane

A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line.

• The vertical axis is called the y-axis.

9-3 The Coordinate Plane

A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line.

• The two axes divide the coordinate plane into four quadrants.

9-3 The Coordinate Plane

A coordinate plane is formed by two number lines in a plane that intersect at right angles. The point of intersection is the zero on each number line.

• The point where the axes intersect is called the origin.

9-3 The Coordinate Plane

Additional Example 1: Identifying Quadrants

Name the quadrant where each point is located.

A. X

B. Y

C. S

Quadrant IV

Quadrant III

Quadrant II

9-3 The Coordinate Plane

Check It Out: Example 1

Name the quadrant where each point is located.

A. V

B. Z

C. T

Quadrant I

y-axis

Quadrant IV

Points on the axes are not in any quadrant.Helpful Hint

no quadrant

9-3 The Coordinate Plane

An ordered pair gives the location of a point on a coordinate plane. 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).

The numbers in an ordered pair are called coordinates. The first number is called the x-coordinate. The second number is called the y-coordinate.

The ordered pair for the origin is (0,0).

9-3 The Coordinate Plane

Additional Example 2A: Locating Points on a Coordinate Plane

Give the coordinates of each point.

XFrom the origin, X is 4 units right and 1 unit down.

(4, –1)

9-3 The Coordinate Plane

Additional Example 2B: Locating Points on a Coordinate Plane

Give the coordinates of each point.

Y

(–2, –3)

From the origin, Y is 2 units left, and 3 units down.

9-3 The Coordinate Plane

Additional Example 2C: Locating Points on a Coordinate Plane

Give the coordinates of each point.

SFrom the origin, S is 3 units left, and 3 units up.

(–3, 3)

9-3 The Coordinate Plane

Check It Out: Example 2A

Give the coordinates of each point.

V

From the origin, V is 4 units right and 2 units up.

(4, 2)

9-3 The Coordinate Plane

Check It Out: Example 2B

Give the coordinates of each point.

Z

(0, 4)

From the origin, Z is 0 units right, and 4 units up.

9-3 The Coordinate Plane

Check It Out: Example 2C

Give the coordinates of each point.

T

From the origin, T is 1 unit right, and 3 units down.

(1, –3)

9-3 The Coordinate Plane

Additional Example 3: Graphing Points on a Coordinate Plane

Graph each point on a coordinate plane.

A. V(4, 2)

B. W(–3, 1)

x

y

–4 –2 0 2 4

4

2

–2

–4

From the origin, move 4 units right, and 2 units up.

VW

From the origin, move 3 units left, and 1 unit up.

9-3 The Coordinate Plane

Additional Example 3: Graphing Points on a Coordinate Plane

Graph each point on a coordinate plane.

C. Z(0, 4)

D. T(1, –3)

From the origin, move 4 units down.

x

y

–4 –2 0 2 4

4

2

–2

–4 Z

TFrom the origin, move 1 unit right, and 3 units down.

9-3 The Coordinate Plane

Check It Out: Example 3

Graph each point on a coordinate plane.

A. L(3, 4)

B. M(–3, –3)x

y

–4 –2 0 2 4

4

2

–2

–4

From the origin, move 3 units right, and 4 units up.

L

M

From the origin, move 3 units left, and 3 units down.

9-3 The Coordinate Plane

Check It Out: Example 3C

Graph each point on a coordinate plane.

C. P(1, –2)

D. G(–4, –2)

From the origin, move 1 unit right and 2 units down.

x

y

–4 –2 0 2 4

4

2

–2

–4

PGFrom the origin, move 4 units left, and 2 units down.