Given a graph G, its line graph L(G) is a graph such that:
- Each vertex of L(G) represents an edge of G, and
- Two vertices of L(G) are adjacent if and only if their corresponding edges share a common vertex in G.
i) Show that L(K5) is nonplanar by obtaining K5 or K3,3 as a minor of L(K5).
ii) Find a planar graph whose line graph is nonplanar.