Q1) Define the Addition map. Q2) Is ZxZ Za group homomorphism? Q3) What is the kernel of +? With what set can you identify ker + ? ZXZ ker + What is the set of cosets and with what set can you Q4) Is there a natural map a: ZxZ identify it? Is it a group? If yes, what is the name of this group? ZXZ Q5) Define a map : Z. ker + Q6) Give the set +(ZXZ)