1. 9.3 Reflections January 25, 2013
Add or subtract Bellwork
1. [2.8 –9.2] + [3.5 6.1]
[6.3 –3.1]
3. Triangle ABC has vertices A(2, –1 ), B(1, 3), and C
(–2, –2). Write a matrix equation that shows how to
find the image matrix that represents the
translation of ABC 4 units left and 5 units up.
Jan 27­9:14 AM
HW pg. 593 #4­22 evens 1

2. 9.3 Reflections January 25, 2013
9.3 Reflections
snoitcelfeR 3.9
Line of reflection: mirror line
Jan 27­10:41 AM
HW pg. 593 #4­22 evens 2

3. 9.3 Reflections January 25, 2013
Jan 27­11:49 AM
HW pg. 593 #4­22 evens 3

4. 9.3 Reflections January 25, 2013
Coordinate Rules for Reflections
snoitcelfeR
x-axis: (x,-y)
y-axis: (-x,y)
y = x: (y, x)
y = -x: (-y,-x)
Jan 27­12:31 PM
HW pg. 593 #4­22 evens 4

5. 9.3 Reflections January 25, 2013
Reflection Theorem: A reflection is an isometry.
Jan 27­11:46 AM
HW pg. 593 #4­22 evens 5

6. 9.3 Reflections January 25, 2013
Reflection Matrix
To find the reflected image, write the reflection matrix to the left
of the pre-image matrix, then multiply.
[ ]
x-axis: 1 0
0 -1 [
y-axis: -1
0
]
0
1
Jan 27­1:34 PM
HW pg. 593 #4­22 evens 6

7. 9.3 Reflections January 25, 2013
HW pg. 593 #4-22 evens
Jan 27­1:33 PM
HW pg. 593 #4­22 evens 7