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## Homework Statement

I'm trying to figure out the interval of convergence of the serie:

[itex]\Sigma^{\infty}_{n=2} \frac{(-1)^{n}x^{n/2}}{nln(n)}[/itex]

## Homework Equations

## The Attempt at a Solution

The book states that the serie isn't a power serie, but a substitution can be used to transform it into a power serie. I tried to pose [itex]y^{n} = x^{n/2}[/itex].

I also know that I must use the ratio test. Maybe there's another way to solve it, but the book states that the ratio test must be used. My problem is that I don't know how to simplify the ln(n+1) term that appears when I do that. Would anyone mind giving me a clue?