Let [tex]F[/tex] be a field. Let [tex] c \in F[/tex].(adsbygoogle = window.adsbygoogle || []).push({});

I am trying to show that if

[tex] c = f^2[/tex] where [tex]f\in F[[x]][/tex], then [tex]f\in F[/tex].

So I am able to get rid of the terms with negative exponent. So now I'm left with a formal power series. Anyone knows how to do this? Thanks!

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# The square of a formal laurent series

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