Reflections across f(x) = x

Directions

Points C, D, and E are graped above. The line

is graphed aboved. Reflect points C,D, & E over the line. 1) Click on the "reflection about line" tool 2) Click on the line of reflection then 3) Click on the point you want to reflect These steps should plot the pre-images C', D' and E'.

Observation

What do you notice about the pre-image and image coordinates? Based on your observations, write a rule describing how the coordinates change when reflected over the line .

PRACTICE: f(x) = x reflections

Use the graph below to answer the questions that follow.

Question 1

Triangle ABC has vertices located at A(9, 0) B(4, 1) C(5, 3) What are the vertices of Triangle A'B'C' given a reflection across the line f(x) = x?

Select all that apply

A
A'(-9, 0) B'(-4, 1) C'(-5, 3)
B
A'(0, 9) B'(1, 4) C'(3, 5)
C
A'(9, 0) B'(4, -1) C'(5, -3)

Check my answer (3)

Question 2

Rectangle WXYZ has vertices located at W(0, 0) X(5, 0) Y(5, 5) Z(0, 5) What are the vertices of Rectangle W'X'Y'Z given a reflection across the line f(x) = x?