Find all z for which the series
∑(in)$^2$z$^n$ converges.
Using the ratio test I got |z| < 1
And it diverges if |z|=1
2026-03-27 05:05:58.1774587958
Is the solution to this power series correct?
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What you did is fine. The only thing that needs to be added to it is that, since it diverges when $|z|=1$, it also diverges when $|z|\geqslant1$. Of course, you can also deduce from the ratio test that the series diverges when $|z|>1$.