4 1 Plot Points in a Coordinate Plane

4. 1 Warm-Up Plot the numbers on a number line. 1. – 4, –

4. 1 Example 1 Give the coordinates of the point. a. A b. B

4. 1 Example 1 b. Point B is 2 units to the right of

4. 1 Guided Practice 1. Use the coordinate plane in Example 1 to give

4. 1 Example 2 Plot the point in a coordinate plane. Describe the location

4. 1 Guided Practice Plot the point in a coordinate plane. Describe the location

4. 1 Example 3 Graph the function y = 2 x – 1 with

4. 1 Example 3 STEP 2 List the ordered pairs: (– 2, – 5),

4. 1 Guided Practice 1 7. Graph the function y = – 3 x

4. 1 Example 4 VOTING In 1920 the ratification of the 19 th amendment

4. 1 Example 4 a. Explain how you know that the table represents a

4. 1 Example 4 SOLUTION a. The table represents a function because each input

4. 1 Example 4 SOLUTION c. In the three election years before 1920, the

4. 1 Guided Practice VOTING 8. The presidential election in 1972 was the first

4. 1 b. Guided Practice Graph the function represented by the table. ANSWER

4. 1 c. Guided Practice Describe any trend in the number of votes cast.

4. 1 Lesson Quiz Give the coordinates of the points. 1. A ANSWER 2.

4. 1 Lesson Quiz Plot the points in a coordinate plane. 3. A( 2,

4. 1 Lesson Quiz 1 5. Graph y = 2 x – 1 with

Slides: 21

Download presentation

4. 1 Plot Points in a Coordinate Plane Warm Up Lesson Presentation Lesson Quiz

4. 1 Warm-Up Plot the numbers on a number line. 1. – 4, – 2, 1, 3 ANSWER 2. – 3, 0, 2, 5 ANSWER 3. 0. 4, 0. 9, 1. 3, 1. 6 ANSWER

4. 1 Example 1 Give the coordinates of the point. a. A b. B SOLUTION a. Point A is 3 units to the left of the origin and 4 units up. So, the x-coordinate is – 3, and the y-coordinate is 4. The coordinates are (– 3, 4).

4. 1 Example 1 b. Point B is 2 units to the right of the origin and 3 units down. So, the x-coordinate is 2, and the y-coordinate is – 3. The coordinates are (2, – 3).

4. 1 Guided Practice 1. Use the coordinate plane in Example 1 to give the coordinates of points C, D, and E. ANSWER C (0, 2), D (3, 1), E (– 2, – 3) 2. What is the y-coordinate of any point on the x-axis? ANSWER 0

4. 1 Example 2 Plot the point in a coordinate plane. Describe the location of the point. a. A(– 4, 4) b. B(3, – 2) c. C(0, – 4) SOLUTION a. Begin at the origin. First move 4 units to the left, then 4 units up. Point A is in Quadrant II. b. Begin at the origin. First move 3 units to the right, then 2 units down. Point B is in Quadrant IV. Begin at the origin and move 4 units down. Point C is on the y-axis. c.

4. 1 Guided Practice Plot the point in a coordinate plane. Describe the location of the point. 3. A(2, 5) ANSWER 4. Quadrant I B(– 1, 0) ANSWER x-axis

4. 1 Guided Practice Plot the point in a coordinate plane. Describe the location of the point. 5. C(– 2, – 1) ANSWER Quadrant III 6. D(– 5, 3) ANSWER Quadrant II

4. 1 Example 3 Graph the function y = 2 x – 1 with domain – 2, – 1, 0, 1, and 2. Then identify the range of the function. SOLUTION STEP 1 Make a table by substituting the domain values into the function.

4. 1 Example 3 STEP 2 List the ordered pairs: (– 2, – 5), (– 1, – 3), (0, – 1), (1, 1), (2, 3). Then graph the function. STEP 3 Identify the range. The range consists of the y-values from the table: – 5, – 3, – 1, 1, and 3.

4. 1 Guided Practice 1 7. Graph the function y = – 3 x + 2 with domain – 6, – 3, 0, 3, and 6. Then identify the range of the function. ANSWER range: 0, 1, 2, 3, and 4

4. 1 Example 4 VOTING In 1920 the ratification of the 19 th 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.

4. 1 Example 4 a. Explain how you know that the table represents a function. b. Graph the function represented by the table. c. Describe any trend in the number of votes cast.

4. 1 Example 4 SOLUTION a. The table represents a function because each input has exactly one output. b. To graph the function, let x be the number of years before or since 1920. Let y be the number of votes cast (in millions). The graph of the function is shown.

4. 1 Example 4 SOLUTION c. In the three election years before 1920, the number of votes cast was less than 20 million. In 1920, the number of votes cast was greater than 20 million. The number of votes cast continued to increase in the three election years since 1920.

4. 1 Guided Practice VOTING 8. 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. a. Explain how you know the graph represents a function. ANSWER The table represents a function because each input has exactly one output.

4. 1 b. Guided Practice Graph the function represented by the table. ANSWER

4. 1 c. Guided Practice Describe any trend in the number of votes cast. ANSWER Sample answer: Before 1972, the number of votes cast increased by 2 million every 4 years. In 1972, the number increased by 5 million and continued to increase by more than 2 million every four years since 1972.

4. 1 Lesson Quiz Give the coordinates of the points. 1. A ANSWER 2. B 1. A( 3, 2) 2. B(0, 1)

4. 1 Lesson Quiz Plot the points in a coordinate plane. 3. A( 2, 4) ANSWER 4. B(3, 0)

4. 1 Lesson Quiz 1 5. Graph y = 2 x – 1 with domain – 4, – 2, 0, 2, 4. Then identify the range ANSWER – 4, – 3, – 2, – 1, 0