2. Reflection is a transformation that produces a mirror
image of an object. It is obtained by rotating the
object by 180 degree about the reflection axis
3. y
Reflection about y
x = x
Initial
Object
x
Reflection about
origin
x = x
y = y
Reflection about x
y = y
8. Example
Example: To make a reflection about the vertical axis x = 1.
Steps:
Subtract 1 from the x-coordinate.
This effectively makes the x = 1 axis coincident with the major
y axis.
Perform the reflection by reversing the sign of the modified x
coordinate.
Add 1 to the reflected coordinate to compensate for the
original subtraction.
9. x1 = x −1
x2 = −(x − )1
x
′ = −(x −1) +1
which simplifies to
x
′ = −x + 2
y
′=y