Log is the principal branch of the log function.

If two non-zero complex numbers $\displaystyle z_{1},z_{2}$

Then show the following:

Log($\displaystyle z_{1}z_{2}$) = Log($\displaystyle z_{1}$) + Log($\displaystyle z_{2}$) - 2N*pi*i, for N = 0 or N = 1

Thanks. Your help is appreciated.