Reflections on a Coordinate plane

Reflections on a Coordinate Plane

Open Ended

Think back to our previous lesson. What does TRANSFORMATION mean in Math?

Open Ended

What does reflection mean to you?

• Are a type of transformation that move a shape by flipping it.
  

• Shapes can be flipped across the x or y axis (point of reflection)
  

• Corresponding Prime points are equidistant from the line of reflection as the pre-image

• The pre-image is the original image and the image is the image after it has been

Reflection

Reflection across the x-axis

Reflection across the y-axis

Open Ended

What do you notice about the image and pre-image?

What similarities do you see? What differences do you see?

Open Ended

What do you notice about the change in points from the pre-image to the image on the previous slides?

Open Ended

What are some difference between reflecting across the x-axis and reflecting across the y-axis?

Multiple Choice

Point Q is located at (4, 5). We want to Reflect across the x-axis.

What would be the location of point Q'?

• (-4, 5)

• (4, -5)

• (4, 5)

• (-4, -5)

Multiple Choice

Point K is located at (-2, 1). We want to Reflect across the y-axis.

What would be the location of point K'?

• (-1, 2)

• (2, 1)

• (-2, -1)

• (2, -1)

Open Ended

Explain the transformation shown on the graph.

Open Ended

What is the meaning of the notation in relation to translations? 

(x, y) → (-x, y)

Open Ended

What is the meaning of the notation in relation to translations? 

(x, y) → (x, -y)

Multiple Choice

Which notation represents a reflection across the y-axis

• (x, y) → (-x, y)

• (x, y) → (x, -y)

Multiple Choice

Which notation represents a reflection across the x-axis

• (x, y) → (-x, y)

• (x, y) → (x, -y)

Multiple Choice

Triangle A,B,C has the coordinates
A: (-8, 8)
B: (-8, 4)
C: (5, 4)

The mapping notation

(x, y) → (-x, y) was used to create this image. What are the coordinates of point B' in the prime image?

• (-8, 4)

• (8, 4)

• (-8, -4)

• (-8, -4)

Open Ended

Summarize:

1) What is your definition of Reflection?

2) How do the notations help with performing reflections in the coordinate plane?

Multiple Select

Choose the topics you still need help understanding. (You can choose more than 1)

• None. I understand everything in today's lesson

• The difference between image and pre-image.

• 
  Performing translations using mapping notation

• The definition of a reflection.