Opened 4 years ago

Last modified 5 weeks ago

#23015 new enhancement

Convert rootof function from giac

Reported by: mforets Owned by:
Priority: major Milestone: sage-9.3
Component: symbolics Keywords:
Cc: rws, frederichan, slelievre Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: #22024 Stopgaps:

Description (last modified by slelievre)

Provide a corresponding Sage function for Giac's rootof. From the inline help of XCAS:

rootof(LstPoly(P),LstPoly(Q)): Polynomial in terms of a root of an irreducible polynomial on Q. Returns P(a) with a the greatest root of Q.

For example,

sage: giac.simplify((exp(2*i*pi/3)+exp(2*i*pi/15))^3)
((-768*i)*(-1)^(2/15)*sqrt(3)-768*(-1)^(2/15)+768*i*(-1)^(4/15)*sqrt(3)-768*(-1)^(4/15)+rootof([[16-16*i,-16+16*i,-400+528*i,144+240*i],[1,0,-30,-40,5]]))/512

This seems different from #22024.

Change History (5)

comment:1 Changed 3 years ago by rws

  • Description modified (diff)

comment:2 Changed 2 years ago by slelievre

  • Cc slelievre added
  • Description modified (diff)
  • Milestone changed from sage-8.0 to sage-8.4

comment:3 Changed 11 months ago by gh-nasser1

fyi, This still shows up in 8.9

var('x')
integrate(x^6/(2*x^5+3)^3,x, algorithm="giac")
NotImplementedError: Unable to parse Giac output: rootof(

comment:4 Changed 3 months ago by mkoeppe

  • Milestone changed from sage-8.4 to sage-9.2

comment:5 Changed 5 weeks ago by mkoeppe

  • Milestone changed from sage-9.2 to sage-9.3
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