First Theorem of Directed Graphs | Digraph Theory

Support the production of this course by joining Wrath of Math to access all my graph theory videos! https://www.youtube.com/channel/UCyEKvaxi8mt9FMc62MHcliw/join 🛍 Check out the coolest math clothes in the world: https://mathshion.com/ Graph Theory course: https://www.youtube.com/playlist?list=PLztBpqftvzxXBhbYxoaZJmnZF6AUQr1mH Graph Theory exercises: https://www.youtube.com/playlist?list=PLztBpqftvzxXtYASoshtU3yEKqEmo1o1L Get the textbook! https://amzn.to/3HvI535 The first theorem of graph theory tells us that the degree sum of a graph is two times the number of edges, or two times its size. A similar theorem is true in directed graph theory, or digraph theory. This theorem states that the sum of the outdegrees of the vertices in a digraph equals the sum of the indegrees, and they're both equal to m, the size of the digraph (the number of directed edges/arcs it has). We'll go over why this theorem is true in today's lesson! Intro to directed graphs: https://www.youtube.com/watch?v=mXoiHgH4mEE First Theorem of Graph Theory: https://www.youtube.com/watch?v=cZPy65LX_Mo ◆ Donate on PayPal: https://www.paypal.me/wrathofmath ◆ Support Wrath of Math on Patreon: https://www.patreon.com/join/wrathofmathlessons Follow Wrath of Math on... ● Instagram: https://www.instagram.com/wrathofmathedu ● Facebook: https://www.facebook.com/WrathofMath ● Twitter: https://twitter.com/wrathofmathedu