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Section Daily Prep 6

You will begin to explore the idea of the cosets of a subgroup in a group. We will see that these partition a group and give us more understanding about the structure of that group.

Subsection Resources for Learning

Use these resources to prepare for class and answer the questions below.
Figure 58. Reference Video for Cosets & Cayley Diagrams

Subsection Important Terms

Definition 59. Cosets of a Subgroup.

Let \(G\) be a group and \(H\leq G\text{.}\) For any \(a \in G\text{,}\) the left coset of \(H\) in \(G\) containing \(a\) is the set
\begin{equation*} aH = \{ah \mid h \in H\}\text{.} \end{equation*}
The right coset of \(H\) in \(G\) containing \(a\) is the set
\begin{equation*} Ha = \{ha \mid h \in H\}\text{.} \end{equation*}
The element \(a\) is called the coset representative of \(aH\) (or \(Ha\)).