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Figure 4.2.8
EXAMPLE 8 Composition of Two Reflections
Let be the reflection about the y-axis, and let be the reflection about the x-axis. In this case
and are the same; both map each vector
into its negative (Figure 4.2.9):
Figure 4.2.9
The equality of and can also be deduced by showing that the standard matrices for and commute:
