1. 4.1- Plot Points in a Coordinate Plane

2. Ordered pairs are used to locate points in a coordinate plane.
y-axis (vertical axis) 5 -5 5
x-axis (horizontal axis) -5
origin (0,0)

3. In an ordered pair, the first number is the x-coordinate
In an ordered pair, the first number is the x-coordinate. The second number is the y-coordinate. Graph. (-3, 2) 5 • -5 5 -5

4. The x-axis and y-axis separate the coordinate plane into four regions, called quadrants.II
(-, +) I
(+, +)
III
(-, -) IV
(+, -)

6. Name the quadrant in which each point is located (-5, 4)II
III IV
None – x-axis
None – y-axis

7. Name the quadrant in which each point is located (-2, -7)II
III IV
None – x-axis
None – y-axis

8. Name the quadrant in which each point is located (0, 3)II
III IV
None – x-axis
None – y-axis

9. Example 1: Give the coordinates of the point.
(1,4)
(-4,3)
(0,3)
(5,1)
(-3,0)
(1,0)
(0,0)
(0,-3)
(-4,-4)
(3,-4)

10. Example 2: Plot the point in a coordinate plane
Example 2: Plot the point in a coordinate plane Describe the location of the point.   a) A(-4,9) b) B(5,0) c) C(0,-8) d) D(7, -2)
A(-4,9)
B(5,0)
D(7,-2)
C(0,-8)

11. Example 3: Graph the function y = ½x + 1 with the
following values of x: -4, -2, 0, 2, and 4.
Step 1: Make a table x
y = ½x + 1 y -4
y = ½(-4) + 1 -1 -2
y = ½(-2) + 1
y = ½(0) + 1 1 2
y = ½(2) + 1 4
y = ½(4) + 1 3 x
y = ½x + 1 y -4
y = ½(-4) + 1 -2
y = ½(-2) + 1
y = ½(0) + 1 2
y = ½(2) + 1 4
y = ½(4) + 1 x
y = ½x + 1 y -4
y = ½(-4) + 1 -2
y = ½(-2) + 1
y = ½(0) + 1 2
y = ½(2) + 1 4
y = ½(4) + 1

13. What is the ordered pair for A?5
(3, 1)
(1, 3)
(-3, 1)
(3, -1)
• A -5 5 -5

14. What is the ordered pair for C?
(0, -4)
(-4, 0)
(0, 4)
(4, 0) 5 -5 5
• C -5