The question is:

Let Log z  = ln \left | z \right | + i \theta where -\pi < \theta \leq \pi and z=\left | z \right | e^{i\theta}, (z\neq 0). Prove that Log is not continuous on  (- \infty,0).

Hint: Consider the sequences {-1+i/n} and {-1-i/n}.

I am not sure how I should be using these sequences in the proof.

Please help!