Opened 13 months ago

Last modified 4 weeks ago

#30434 new defect

Factorization over C doesn't work

Reported by: gh-galashin Owned by:
Priority: major Milestone: sage-9.5
Component: symbolics Keywords: factor, complex
Cc: slelievre Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by slelievre)

The method factor doesn't correctly factor symbolic expressions over the complex numbers.

sage: a, b = var("a, b")
sage: (a^2 - 2*I*a*b - b^2).factor()
a^2 - 2*I*a*b - b^2
sage: ((a - I*b)^2).expand()
a^2 - 2*I*a*b - b^2

Change History (5)

comment:1 Changed 13 months ago by chapoton

Note that

sage: (a^2-2*I*a*b-b^2)._fricas_().factor().sage()                              
(I*a + b)^2
sage: (a^2-2*I*a*b-b^2)._giac_().factor().sage()                                
(a - I*b)^2

comment:2 Changed 13 months ago by slelievre

  • Cc slelievre added
  • Component changed from PLEASE CHANGE to symbolics
  • Description modified (diff)
  • Keywords factor complex added
  • Type changed from PLEASE CHANGE to defect

comment:3 Changed 11 months ago by mkoeppe

  • Milestone changed from sage-9.2 to sage-9.3

comment:4 Changed 4 months ago by mkoeppe

  • Milestone changed from sage-9.3 to sage-9.4

Moving to 9.4, as 9.3 has been released.

comment:5 Changed 4 weeks ago by mkoeppe

  • Milestone changed from sage-9.4 to sage-9.5
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