Extension of valuation [closed]

I found the lots of way to extend the valuation for transcendental case. But our case here is algebraic. We know that in an algebraic extension, the extension of DVR is again a DVR. How can we extend the 2-adic valuation from Q to Q(sqrt(2)) explicitly? Thank you.

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This is not a research-level question, so I've voted to close it. – Andreas Blass Dec 30 2011 at 23:13
This is in Cassels-Frohlich, or in Cassels' Local Fields, for example. – Daniel Litt Dec 31 2011 at 1:42