g is holomorphic on the open unit ball and continuous on
the closure\ z0 . this pt z0 is on the boundary. if g has
expansion about 0 of form \sum a_n x^n then
prove that \lim_{n\to\infty} \frac{a_n}{a_{n+1}} = z_0

any sort of hints would be helpful, seems like it is asking
for the 1 over the limit of ratio test for the series at 1.
still not sure how to relate this to z0