Show Q[x]/(x^2-4x+4) has infinite nilpotent elements

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Homework Statement



Let R = Q[x]/(x^2-4x+4). Show that R has infinitely many nilpotent elements.

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The Attempt at a Solution



I see that x^2-4x+4 = (x-2)(x-2) and that a nilpotent means a^2 = 0. Other than that, I'm not sure where to start.
 
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Let \varphi:\mathbb{Q}[x]\rightarrow \mathbb{Q}[x]/(x^2-4x+4) be the quotient map. Can you show that \varphi(x-2) is nilpotent? Can you in some way use this to obtain more nilpotents?
 
Thanks for the direction, I think I got something that will work.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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