Symmetry on the Coordinate Plane

Symmetry on the Coordinate Plane

When the signs ONLY of two coordinates differ, there must have been a reflection across one or both of the axes.

Multiple Choice

What is the quadrant circled in the photo?

• I

• II

• III

• IV

Multiple Choice

Which quadrant would point (-2,4) be located in?

• I

• II

• III

• IV

Open Ended

How do you make a number's opposite?

Multiple Select

Select all of the examples of opposite numbers

• 2, -2

• 1/2 , -1/2

• 0.22, -0.22

Open Ended

How are opposite numbers similar, and how are they different?

Opposites

• Opposites are similar because they have the same absolute value, but they are different because opposites are on opposite sides of zero.

Open Ended

What did you notice about the location of the points that had the same x-coordinate, but opposite y-coordinates?

Open Ended

What did you notice about the location of the points that had the same y-coordinate, but opposite x-coordinates?

Open Ended

What did you notice about the location of the points when BOTH coordinates changed signs?

Open Ended

When you think about the word REFLECTION. What do you think?

Reflection across the x-axis

• (x,y) to (x, -y)

• ex. (2,3) to (2,-3)

• ex. (3, -4) to (3, 4)

• keep the x the same and negate the y.

Reflection across the y-axis

• (x,y) to (-x,y)

• ex. (2,3) to (-2,3)

• ex. (-4,2) to (4,2)

• keep the y and NEGATE THE X

Multiple Choice

• (-2,-4)

• (-2,4)

• (2,-4)

• (2,4)

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• A

• B

• C

• D

Fill in the Blank

Reflect Point B (9, -2) over the x-axis. What is the ordered pair AFTER the reflection?

Fill in the Blank

Reflect Point B (-2, -2) over the x-axis. What is the ordered pair AFTER the reflection?

Fill in the Blank

Reflect Point B (3, 4) over the y-axis. What is the ordered pair AFTER the reflection?

Fill in the Blank

Reflect Point B (-5, 4) over the y-axis. What is the ordered pair AFTER the reflection?

Multiple Select

​How can this reflection be described? Select all that apply

• Point B is located in Quadrant III

• The y-values differ only by signs

• The x-values differ only by signs

• Point B is located in Quadrant I

• The X-values remain the same.

Multiple Select

Which of the following statements are true about the two points, B and B '

Select all that apply.

• Point B′ has a positive x-coordinate.

• Only Point B has a negative x-coordinate

• Point B is in Quadrant III and Point B' is in Quadrant II

• Point B has a negative Y-coordinate and Point B' has a positive Y-coordinate

Multiple Choice

If (x,y) reflects to (-x,y), what axis did it reflect over?

• x-axis

• y-axis

• both axes

Multiple Choice

If (x,y) reflects to (x,-y), what axis did it reflect over?

• x-axis

• y-axis

• both axes

Multiple Choice

If (x,y) reflects to (-x,-y), what axis did it reflect over?

• x-axis

• y-axis

• both axes

Poll

Outcome Review

• I definitely understand how reflections work on a coordinate grid

• I kinda understand how reflections work on a coordinate grid

• I have not clue what a reflection is on a coordinate grid... I though what I see in the mirror is a reflection.........