https://tube.cosmicflow.space/videos/watch/2a1cf47a-ce5e-4c37-bf79-09ca33f33a7f This lecture is part of an online undergraduate course on complex analysis. We review the basic arithmetic of complex numbers, and given some applications to some problems in number theory related to sums of two squares. At the end we briefly cover the quaternions. For the other lectures in the course see https://www.youtube.com/playlist?list=PL8yHsr3EFj537_iYA5QrvwhvMlpkJ1yGN Tue, 06 Oct 2026 15:31:42 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://tube.cosmicflow.space https://tube.cosmicflow.space/lazy-static/avatars/8891227d-e60f-40aa-88be-4c856c6a73dc.png https://tube.cosmicflow.space/videos/watch/2a1cf47a-ce5e-4c37-bf79-09ca33f33a7f All rights reserved, unless otherwise specified in the terms specified at https://tube.cosmicflow.space/about and potential licenses granted by each content's rightholder.