We have discussed the terms radius and diameter in a previous video. Here we work through two simple proofs which involve these concepts. First we show that the complement of a disconnected graph has diameter at most 2. Then we show that any given graph is the centre of some connected graph (the centre of a graph is the set of vertices whose eccentricity is equal to the radius of the graph -ie those vertices with minimum eccentricity).
-- Bits of Graph Theory by Dr. Sarada Herke.
Related videos:
• Graph Theory: 51. Eccentricity, Radius & D... - 51. Eccentricity, Radius and Diameter
• Graph Theory: 50. Maximum vs Maximal - 50. Maximum vs Maximal
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