Hi everybody,

How to show that: $\displaystyle \forall a \in \mathbb{C}*, \exists z_0 \in \mathbb{C}$ such as: $\displaystyle a=e^{z_0}$, and if $\displaystyle e^z=a $then $\displaystyle \exists k \in \mathbb{Z}: z=z_0+2k\pi$, i don't know how to show that, can you help me please???

And thanks anyway.