Math in… Social Networks

When you join a social network like Facebook, Instagram, X, LinkedIn, or TikTok, you join a graph based on who you follow.

In graph theory, a graph is a network of vertices and edges that can represent objects (e.g., people or countries) and relationships they have or don’t have (e.g., being friends or sharing a border).

Can you see why a social network’s algorithm might suggest that the people in blue shirts follow or friend each other? What other things could it do with a graph like this?