Now we can use matrixarithmeticto expressreflections.
Givena point in the coordinateplane,we will use matrixmultiplicationto reflectthe point.Note:In
all the matrixmultiplicationsthat follow, we multiply on theleftby a reflectionmatrixon theright.
Remember(fromabove),left and right placementmatter!
Reflectionin the -axis:Multiplyany pointor polygonmatrixby.
Proof.Reflectionin the -axis:Multiplyany pointor polygonmatrixby.
Proof.Reflectionin : Multiplyany pointor polygonmatrixby.
Proof. The proofis availablein the LessonExercises.Example 4