Minimal polynomials and invertibility

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Let T\in L(V). Let g(x)\in F[x] and let m(x) be the minimal polynomial of T. Show that g(T) is invertible \Leftrightarrow \gcd (m(x),g(x))=1.

Backwards is easy. For forwards, suppose I say that g(T) is invertible implies that g(T)(v)=0 \Rightarrow v=0 and therefore g(x) prime, therefore it is not divisible, and therefore \gcd (g,m)=1. Is that correct?

Why is latex not showing up?
 
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Treadstone 71 said:
Let T\in L(V). Let g(x)\in F[x] and let m(x) be the minimal polynomial of T. Show that g(T) is invertible \Leftrightarrow \gcd (m(x),g(x))=1.

Backwards is easy. For forwards, suppose I say that g(T) is invertible implies that g(T)(v)=0 \Rightarrow v=0 and therefore g(x) prime, therefore it is not divisible, and therefore \gcd (g,m)=1. Is that correct?

Why is latex not showing up?

They had some sort of server disaster yesterday, I take it.

-Dan
 
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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