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SolveAnEvenPolynomialOverASymbolicBiquadratic​(AngouriMath.​Entity,​AngouriMath.​Entity.​Variable,​System.​Boolean)

 Method (no overloads)

Summary

A polynomial in x^2 over a + b x^2 + c x^4 with a symbol in it, by the
two roots in x^2: with q = sqrt(b^2 - 4 a c) and
r = (-b ± q)/(2c), (d + e x^2)/(a + b x^2 + c x^4) is
(d + e r_1)/(q (x^2 - r_1)) - (d + e r_2)/(q (x^2 - r_2)), and
1/(x^2 - r) is atan(x/sqrt(-r))/sqrt(-r) for any complex r. A
higher even degree is divided down first, and an odd numerator is left to the
substitution u = x^2.

Remarks

The partial fractions read written factors, and a + b x^2 + c x^4 is written
as one; over the rationals it is factored, over symbols it was declined, and Rubi's
quartic files -- (d x)^m (a + b x^2 + c x^4)^p and the next four -- lost the
even numerators to it: x^2/(a + b x^2 + c x^4), (d + e x^2)/(...).
Exact wherever the two roots differ, which is the generic case; a discriminant
that is zero as written declines, the square of a quadratic being another shape.
https://github.com/asc-community/AngouriMath/issues/718

























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