Transformations: Reflection
By: Yosep Rhe & Helen Yoo
Definition
A type of transformation that reflects,or "flips", a graph or figure across a line,called the line of reflection. A reflection is a type of isometry. An isometry (aka congruence transformation or rigid motions) is a transformation that doesn't change the shape or size of a figure.
Rules of Reflection
Reflect over...
X-axis: (x,y) -> (x,-y)
Y-axis: (x,y) -> (-x,y)
Y=X: (x,y) -> (y,x)
Reflection over x-axis (Click on the image to see the image for all...)
Rule: (x,y) -> (x,-y)
Coordinates:
A: (-2,1) -> (-2,-1)
B: (2,4) -> (2,-4)
C: (4,2) -> (4,-2)
Reflection over y-axis
Rule: (x,y) -> (-x,y)
Coordinates:
A: (2,2) -> (-2,2)
B: (4,4) -> (-4,4)
C: (5,1) -> (-5,1)
Reflection over y=x
Rule: (x,y) -> (y,x)
Coordinates:
A: (-4,2) -> (2,-4)
B: (-3,-1) -> (-1,-3)
C: (-5,-2) -> (-2,-5)