WARM UP 1.Evaluate when x = -3 and y = Evaluate (2x)² when x = 5. 5 Minutes Remain x - y 4

WARM UP 1.Evaluate when x = -3 and y = Evaluate (2x)² when x = 5. 4 x - y 4

WARM UP 1.Evaluate when x = -3 and y = Evaluate (2x)² when x = 5. 3 x - y 4

WARM UP 1.Evaluate when x = -3 and y = Evaluate (2x)² when x = 5. 2 x - y 4

WARM UP 1.Evaluate when x = -3 and y = Evaluate (2x)² when x = 5. 1 x - y 4

WARM UP 1.Evaluate when x = -3 and y = Evaluate (2x)² when x = 5. 0 x - y 4

4.1 The Coordinate Plane GOAL: Plot points in a coordinate plane KEY WORDS: Coordinate plane Origin X-axis, y-axis Ordered pair X-coordinate Y-coordinate Quadrant Scatter plot

4.1 The Coordinate Plane A coordinate plane is formed by two real number lines that intersect at a right angle at the origin. The horizontal axis is the x-axis and the vertical axis is the y-axis. Origin (0,0) Vertical or y-axis Horizontal or x-axis

4.1 The Coordinate Plane Each point in a coordinate plane corresponds to an ordered pair or real numbers. The first number in an ordered pair is the x-coordinate and the second number is the y- coordinate. On the graph, the ordered pair (3,-2) has an x- coordinate of 3 and a y-coordinate of -2. (3,-2)

4.1 The Coordinate Plane EXAMPLE 1: Identify Coordinates Write the ordered pairs that correspond to points A, B, C and D. SOLUTION Point A is 3 units to the right and 2 units down from the origin. So, its x-coordinate is 3 and its y coordinate is -2. the ordered pair is (3,-2). A B C D

4.1 The Coordinate Plane EXAMPLE 1: Identify Coordinates Point B has coordinates: (-2,-1) Point C has coordinates: (0,2) Point D has coordinates: (-3,4) A B C D

EXAMPLE 2: Plot the point in a coordinate plane a.(3, 4) SOLUTION To plot the point (3,4), start at the Origin. Move 3 units to the right and 4 units up. (3,4)

4.1 The Coordinate Plane EXAMPLE 2: Plot the point in a coordinate plane a.(-2,-3) SOLUTION To plot the point (-2, -3), start at the origin. Move 2 units to the left and 3 units down. (-2, -3)

4.1 The Coordinate Plane The x-axis and the y-axis divide the coordinate plane called quadrants. Each point in a coordinate plane is locate in one of the four quadrants or on one of the axes. Quadrant IV (+,-) Quadrant III (-,-) Quadrant II (-,+) Quadrant I (+,+)

4.1 The Coordinate Plane You can tell which quadrant a point is in by looking at the signs of the coordinates. In the graph the point (4,3) is in Quadrant I. The point (0,-4) is on the y-axis and is not inside any of the four quadrants. Quadrant IV (+,-) Quadrant I (+,+) Quadrant III (-,-) Quadrant II (-,+) (4,3)(4,3)(4,3)(4,3) (0,-4)

4.1 The Coordinate Plane EXAMPLE 3: Identify Quadrants Name the Quadrant the point is in. a)(-2,3)b) (4,-2) SOLUTION a)(-2,3) is in Quadrant II because its x- coordinate is negative and its y- coordinate is negative. b)(4, -2) is in Quadrant IV because its x- coordinate is positive and its y- coordinate is negative Quadrant IV (+,-) Quadrant III (-,-) Quadrant II (-,+) Quadrant I (+,+) (4,-2) (-2,3) YOU ARE CERTIFIED!

4.1 The Coordinate Plane YOUR TURN Plot the point in a coordinate plane. 1.(-2,5)2. (3,7)3. (-1,-3)4. (-2,0) Name the quadrant the point is in. 5. (-5,-3)6. (2,0)7. (4,-1)8. (-3,6)

4.1 The Coordinate Plane CLASSWORK/HOMEWORK Page 206 #s 1-26