Isomorphism Theorems: Third Isomorphism Theorem

This lecture explores the third isomorphism theorem in group theory, focusing on quotient groups and a categorical perspective. The theorem states that for a group G and a subgroup N, if K is a subgroup of G containing N, then G/K is isomorphic to (G/N)/(K/N). The proof involves showing that certain sets are equal and considering the surjectivity of the homomorphism. Notations and calculations are used to illustrate the theorem's application.