1. Lesson 4.1 Plot Points in a Coordinate Plane
Essential Question: How do you plot points in a coordinate plane?

2. Before we start…
Label the coordinate plane: x-axis, y-axis, Quadrants I – IV, origin

3. 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.

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

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

6. Name the points in the coordinate planeB E F

7. 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.

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

9. How can I graph a function?
Any function can be graphed by making an x/y table and plotting the points.
If you are given a specific domain, then you will make an x/y table to graph.

15. Explain how you know that the table represents a function.
Voting In 1920 the ratification of the 19th amendment to the United States Constitution gave women the right to vote. The table shows the number (to the nearest million) of votes cast in presidential elections both before and since women were able to vote.
Explain how you know that the table represents a function.
Graph the function represented by the table.
Describe any trend in the number of votes cast.
Years before or since 1920
-12 -8 -4 4 8 12
Votes (millions) 15 19 27 29 37 40

16. Explain how you know that the table represents a function.
Voting The presidential election in 1972 was the first election in which 18-year-olds were allowed to vote. The table shows the number (to the nearest million) of votes cast in presidential elections both before and since 1972.
Explain how you know that the table represents a function.
Graph the function represented by the table.
Describe any trend in the number of votes cast.
Years before or since 1972
-12 -8 -4 4 8 12
Votes (millions) 69 71 73 78 82 87 93

17. Astronaut Photography Astronauts use a coordinate system to describe the location of objects they photograph from space. The x-axis is the equator, 0° latitude. The y-axis is the prime meridian, 0° longitude. The names and coordinates of some lakes photographed from space are given. Use the map to determine on which continent each lake is located.
Lake Kulundinskoye 80,53 d. Lake Champlain −73, 45
Lake Van 43, e. Lake Viedma −73, −50
Lake Saint Clair −83, 43 f. Starnberger Lake 12, 48

18. What is a transformation?
Applying a rule to a set of points that produces an image

19. What is a translation?
A transformation that moves every point in a figure the same distance in the same direction. Horizontally, vertically, both

20. What is a vertical stretch or shrink?
A transformation that moves every point in a figure away from the x-axis or toward the x-axis

21. What is a reflection?
A transformation that flips a figure in a line

23. Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0
Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0 . Perform the indicated transformation.
𝑥,𝑦 → 𝑥,𝑦−5

24. Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0
Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0 . Perform the indicated transformation.
𝑥,𝑦 → 𝑥,𝑦+1

25. Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0
Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0 . Perform the indicated transformation.
𝑥,𝑦 → 𝑥,−𝑦

26. Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0
Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0 . Perform the indicated transformation.
𝑥,𝑦 → 𝑥,4𝑦

27. Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0
Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0 . Perform the indicated transformation.
𝑥,𝑦 → 𝑥+2,𝑦+3

28. Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0
Square ABCD has vertices at 0,0 , 0,2 , 2,2 and 2,0 . Perform the indicated transformation.
𝑥,𝑦 → 𝑥−1,𝑦+4

29. A square has vertices at 0,0 , 0,3 , 3,3 and 3,0
A square has vertices at 0,0 , 0,3 , 3,3 and 3,0 . Tell how you could use a transformation to move the square so that it has new vertices at 0,0 , 0,−3 , 3,−3 and 3,0 .

30. How do you plot points in a coordinate plane?

31. Ticket Out the Door
Give the coordinates of Point A on the coordinate plane.