*in which meet the orthogonal group and we rotate and reflect in two and three dimensions.
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# orbit

# Groups Lecture 18

*in which we meet the quaternions, start exploring matrix groups and act with matrices on vectors and on matrices.
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# Groups Lecture 14

*in which we meet several standard actions and prove Cayley’s Theorem.
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# Groups Lecture 13

*in which we meet orbits and stabilisers and prove the Orbit-Stabiliser Theorem.
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# Groups Lecture 19

*in which we act with matrices on vectors and on matrices, and meet the orthogonal group.
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# Groups Lecture 14

*in which we meet orbits and stabilisers and prove the Orbit-Stabiliser Theorem.
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