Do just number 6 Determine Whether P4 is an induced subgraph
Do just number 6.
Solution
A complete bipartite graph is a graph whose vertices can be partitioned into two subsets V1 and V2 such that no edge has both endpoints in the same subset, and every possible edge that could connect vertices in different subsets is part of the graph. That is, it is a bipartite graph (V1, V2, E) such that for every two vertices v1 V1 and v2 V2, v1v2 is an edge in E. A complete bipartite graph with partitions of size |V1|=m and |V2|=n, is denoted Km,n;
The maximum number of edges in an n-vertex triangle free graph is {\\displaystyle \\lfloor n^{2}/4\ floor .}
In other words, one must delete nearly half of the edges in Kn to obtain a triangle-free graph.
