# Groups Lecture 17

in which we explore conjugacy classes in $S_n$ and $A_n$, and prove that $A_5$ is simple.

# Groups Lecture 8

in which we show that the sign of a permutation is a surjective group homomorphism, meet cosets and prove Lagrange’s Theorem.

# Groups Lecture 21

in which we meet the Möbius group as transformations of the Riemann Sphere.

# Groups Lecture 17

in which we explore conjugacy classes in $S_n$ and $A_n$, and prove that $A_5$ is simple.

# Groups Lecture 8

in which we show that the sign of a permutation is a surjective group homomorphism, and meet cosets.