Given min. polynomial of a, find min. polynomial of 1/a

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SUMMARY

The minimal polynomial of the element \( a \) over the rationals is given as \( x^4 + x + 8 \). To find the minimal polynomial for \( \frac{1}{a} \) over \( \mathbb{Q} \), one effective method is to multiply the equation \( a^4 + a + 8 = 0 \) by \( \frac{1}{a} \) repeatedly. This approach leads to the derivation of the minimal polynomial for \( \frac{1}{a} \) through algebraic manipulation of the original polynomial.

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Homework Statement


Given that the minimal polynomial of a over rationals is x^4+x+8, find the minimal polynomial for 1/a over Q.


Homework Equations


I know there is a lot of work done out there for finding the min. polynomials of a^k for k>0, however I've never seen anything with a^k for k<0. I have no intuition where to start with this problem, just wondering if there are methods out there.
 
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You know that

a^4+a+8=0

An obvious thing to do is to multiply both sides by \frac{1}{a} multiple times.
 
Yea I realized this soon after posting, thanks for the help anyway.
 

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