Lesson 1.8 The Coordinate Plane Essential Question: How do you identify and plot points in the coordinate plane?

Before we start… Looking at the graph below, when the snow is 30 inches deep how many rabbits are there?

What is the coordinate plane? A plane that is made by the intersection of two number lines, a vertical line, the y-axis, and a horizontal line, the x-axis.

What is the origin? The point where the x-axis and y-axis meet.

What is a quadrant? One of the four regions that is formed when the x and y-axis are drawn in the coordinate plane.

−3,2 What is an ordered pair? x y A point in the coordinate plane, where the first number is the x-coordinate and the second number is the y-coordinate. x y −3,2

How do you identify a point in the coordinate plane? Determine how many units left or right of the origin the point is located for the x-coordinate. above or below the origin the point is located for the y-coordinate.

Name the points in the coordinate plane

Name the points in the coordinate plane

Name the points in the coordinate plane with your partner.

How do you plot points in a coordinate plane? Begin at the origin and move to the right if the x-coordinate is positive and left if negative Then move up if the y-coordinate is positive or down if negative.

Plot the point in a coordinate plane. B (3, -2) C (0, -4)

Plot the point in a coordinate plane. B (0, 3) C (-2, -1)

Plot the point in a coordinate plane. B (-3, 5) C (2, -6)

Plot the point in a coordinate plane. B (5, 1) C (3, -7)

Plot the point in a coordinate plane. B (6, 7) C (5, -4)

What is a scatter plot? A graph used to determine whether there is a relationship between paired data.

How do you make a scatter plot? To make a scatter plot, you treat the data as ordered pairs. Let x represent the independent data and y represent the dependent data. Plot the ordered pairs as points in a coordinate plane.

Pine Trees The table gives the ages and heights of 10 pine trees Pine Trees The table gives the ages and heights of 10 pine trees. Make a scatter plot of the data. Then make a conclusion about the data. Age 1 6 10 13 18 21 32 36 39 Height 2 4 8 14 16 23 31 34

Greece Flag The national flag of Greece has a fixed width-to-length ratio. Some possible widths and lengths of a Greek flag are shown below. Make a scatter plot of the data. Width 2 4 6 8 10 12 14 Length 3 9 15 18 21

Test Scores and Absences The table shows test scores and the number of absences related to the test score. Make a scatter plot of the data. Then make a conclusion about the data. Test Score 100 95 90 85 80 75 70 65 60 55 50 Absences 2 3 5 7 8 9 11 12 15

Grapefruit The table shows the price (in dollars) for one pound of grapefruit for the years 1997 through 2002. Make a scatterplot of the data where x represents the years since 1997 and y represents the price (in dollars). Years since 1997 1 2 3 4 5 Price (dollars) 0.53 0.55 0.58 0.60 0.62

How do you identify and plot points in the coordinate plane?

Ticket Out the Door Give the coordinates of Points F and G.