Is x^2+1 Irreducible Over Finite Field F_2?

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Homework Statement


Is f(x)=x^2+1 irreducible in \mathbb{F}_2[x]
If not then factorise the polynomial.




The Attempt at a Solution



\mathbb{F}_2[x]=\{0,1\}
f(0)=1
f(1)=1+1=0
Hence the polynomial is not irreducible
 
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jimmycricket said:

Homework Statement


Is f(x)=x^2+1 irreducible in \mathbb{F}_2[x]
If not then factorise the polynomial.




The Attempt at a Solution



\mathbb{F}_2[x]=\{0,1\}
f(0)=1
f(1)=1+1=0
Hence the polynomial is not irreducible
Looks good.
 
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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