The Cauchy-Goursat Theorem

From a channel Lumen includes in full: Gamma Digamma posts a rigorous proof-based linear algebra series (dual spaces, quotient spaces, annihilators) and careful derivations of integrals and special functions.

A 15-minute video from Gamma Digamma's catalogue; the title names its topic.

Video by Gamma Digamma, played through YouTube's embedded player.