ASKSAGE: Sage Q&A Forum - Latest question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Fri, 24 Nov 2017 11:17:56 -0600Factoring polynomials with symbolic expressionshttp://ask.sagemath.org/question/39772/factoring-polynomials-with-symbolic-expressions/ This question is about writing some code that factors a desired polynomial within $\mathbb{Q}$, $\mathbb{R}$ and $\mathbb{C}$ for educational purposes.
So far, I have the following code:
@interact
def _(p = input_box(default=x^5 + x^4 - 8*x^3 + 11*x^2 - 15*x + 2, label = 'P(x) = ')):
q.<x> = PolynomialRing(QQ, 'x')
r.<x> = PolynomialRing(RR, 'x')
c.<x> = PolynomialRing(CC, 'x')
a.<x> = PolynomialRing(AA, 'x')
qp = PolynomialRing(QQ, 'x')(p)
print(factor(qp))
rp = r(p)
print(factor(rp))
cp = c(p)
print(factor(cp))
ap = a(p)
print(factor(ap))
whose output is
(x - 2) * (x^4 + 3*x^3 - 2*x^2 + 7*x - 1)
(x - 2.00000000000000) * (x - 0.147637797932293) * (x + 3.96552349222940) * (x^2 - 0.817885694297105*x + 1.70805524786870)
(x - 2.00000000000000) * (x - 0.408942847148552 - 1.24129810909174*I) * (x - 0.408942847148552 + 1.24129810909174*I) * (x - 0.147637797932293) * (x + 3.96552349222940)
(x - 2.000000000000000?) * (x - 0.1476377979322930?) * (x + 3.965523492229398?) * (x^2 - 0.8178856942971048?*x + 1.708055247868697?)
The factorization is perfect, but I would like the output to be symbolic whenever possible (ie. written with radicals instead of decimals). I know about the use of the ring 'AA' and that the numbers ending with '?' may be translated into symbolic, but I do not know the smartest way to do this.
Which would be the smartest way to achieve this goal? In the same way, ideas to improve the previous code are also welcomejepstraFri, 24 Nov 2017 11:17:56 -0600http://ask.sagemath.org/question/39772/