# Homework Help: Prove that a rational root of a monic polynomial is an integer. Use this to prove

1. Apr 21, 2012

### Edelman

1. The problem statement, all variables and given/known data

Prove that a rational root of a monic polynomial is an integer. Use this to prove that the $\sqrt{2}$ is irrational.

2. Relevant equations

3. The attempt at a solution

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I am really not sure where to begin?

2. Apr 21, 2012

### Office_Shredder

Staff Emeritus
Re: Prove that a rational root of a monic polynomial is an integer. Use this to prove

What about the polynomial x-1/2? It seems like there are some conditions missing from your problem statement. I'm guessing that your polynomial is supposed to have integer coefficients - if you start with the case when the polynomial is a quadratic, once you figure that out it should be clear how to proceed with the general case