2 questions about complex numbers

Q1) Prove that for any two complex numbers and , . Is it true to write Arg Arg Arg . Support your ideas geometrically.

Q2) Show that has distinct values for natural number . What can you say about non-natural values of ? Why?

For question 1, i know that, if one the argument is negative, that equation isn't true because of essential argument thing but i don't know how to explain it at exam paper and how to support it geometrically.

For question 2, i didn't understand a thing. so don't know where to begin solving.