What is the dramatic importance of act II scene ii to the play Hamlet?

Claudius and Gertrude are trying to figure out why Hamlet is acting so insanely. So they ask his college friends Rosencratz and Guildenstern to ask Hamlet what's bothering him. also. Polonius tries to ask Hamlet what bothering him. This brings up one of the important question in the play: Is Hamlet really insane?