h.froot

来自「强大的数学工具包」· FROOT 代码 · 共 45 行

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                         *   froot   *
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        "finding root"
        SYNTAX: X = froot(p,P)
                X = froot(Q)

        p is an expression whose value is a prime.
        In the first case, P is a univariate polynomial over Z.
        In the second case, Q is a univariate polynomial over
        Z/pZ, where p is a prime, over GF(p^n), over Z, Q or R.

        In the first case, froot computes the roots of P over Z/pZ. 
        In the second case, froot computes the roots of Q over Z/pZ,
        over GF(p^n) or in the last three cases over C.
        X is assigned such a root of P (or Q), if there exists one.

        All roots are stored in AV (see "?avfunc").

        Warning: If p > 2^30, the primality of p is not tested.
                 If you want to compute the roots of Q over C
                 and the result is not satisfactory, then increase
                 the precision via DIGITS (see "? flfunc").


        Example 1: (correct)

                froot(5,x^2+1)


        Example 2: (correct)

                froot(MOD(x^3+2*x+1))


        Example 3: (correct)

                froot(GF(A*x^3+x^2+A^4+3))


        Example 4: (correct)

                froot(x^4-2)