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For example I give wolfram alpha the equations $a^2=b, b^2 = c, c^2 = a$ to solve, and I get the following as answers. what wolfram alpha gave me

However, I want $a,b,c$ to be the three roots of a degree $3$ polynomial, is there anyway to utilize the process so I don't have to type each set of solutions in manually?

(This is my first time asking a question, hopefully I have made myself clear)

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    $\begingroup$ Not clear, how are you going to get the 7-root from a 3rd degree polynomial? $\endgroup$
    – yarchik
    Commented Mar 7, 2020 at 8:39
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    $\begingroup$ If a, b, and c are the roots of the polynomial then the polynomial is just Times @@ (x - {a, b, c}) $\endgroup$
    – Bob Hanlon
    Commented Mar 7, 2020 at 15:58

2 Answers 2

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This site is about Mathematica and the Wolfram language, not WolframAlpha.

eqns = {a^2 == c, b^2 == a, c^2 == b};

The solutions are

solns = Solve[eqns, {a, b, c}]

enter image description here

Verifying the solutions

(And @@ eqns) /. solns

(* {True, True, True, True, True, True, True, True} *)

The polynomials (with duplicates removed)

(polys = Times @@ (x - {a, b, c}) /. solns // 
    DeleteDuplicates) // TraditionalForm

enter image description here

For alternate representations

polys // Expand // FullSimplify // TraditionalForm

enter image description here

The real solutions are

solnsR = Solve[eqns, {a, b, c}, Reals]

(* {{a -> 0, b -> 0, c -> 0}, {a -> 1, b -> 1, c -> 1}} *)

(polysR = Times @@ (x - {a, b, c}) /. solnsR) // TraditionalForm

enter image description here

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This is doable in a much more compact way than the previous answer:

Collect[x^3 + C[2] x^2 + C[1] x + C[0] /. 
        SolveAlways[{x^3 + C[2] x^2 + C[1] x + C[0] == (x - a) (x - b) (x - c),
                     a^2 == b, b^2 == c, c^2 == a}, x], x, FullSimplify] // Union
   {x^3, -1 + 3 x - 3 x^2 + x^3,
    -1 - 1/2 I (-I + Sqrt[7]) x + 1/2 (1 - I Sqrt[7]) x^2 + x^3,
    -1 + 1/2 I (I + Sqrt[7]) x + 1/2 (1 + I Sqrt[7]) x^2 + x^3}

and to pick out real solutions,

Select[%, VectorQ[Im[CoefficientList[#, x]], PossibleZeroQ] &] // Factor
   {x^3, (-1 + x)^3}
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