# Prime ideal question (abstract algebra)

## Homework Statement

Let D = Z[sqrt(10)], and let P be the ideal (2,sqrt(10)) 10). Prove that P is a prime
ideal of D.

## The Attempt at a Solution

Not sure where to start. I think elements are of the for a+b*sqrt(10), a,b integers.

Any hints as to what to do next?

Hi Metric_Space!

So your ideal is $\mathfrak{p}=(2,\sqrt{10})$?

The first thing I would do is calculate $\mathbb{Z}[\sqrt{10}]/\mathfrak{p}$ and check whether this is an integral domain...

Right..and there is a theorem that relates Z[10−−√]/p to prime ideals I think, right?

Right..and there is a theorem that relates Z[10−−√]/p to prime ideals I think, right?

Uuh, maybe. But what I'm going for is that p is a prime ideal in a commutative ring R if and only if R/p is an integral domain...

cool..yes, I have a theorem like the one you mention -- that's a good start. Thanks for the hint.