Opened 5 years ago

Closed 7 months ago

#24231 closed defect (invalid)

Maxima's demoivre() doesn't work with hyperbolic functions.

Reported by: charpent Owned by:
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: symbolics Keywords: maxima, demoivre, cosh, sinh
Cc: slelievre Merged in:
Authors: Reviewers: Emmanuel Charpentier, Samuel Lelièvre
Report Upstream: Reported upstream. Developers deny it's a bug. Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by slelievre)

A nice one :

sage: [(t,t(x)._maxima_().exponentialize().demoivre().sage()) for t in [sin,cos,
....: tan,sinh,cosh,tanh]]

[(sin, sin(x)),
 (cos, cos(x)),
 (tan, sin(x)/cos(x)),
 (sinh, -1/2*e^(-x) + 1/2*e^x),
 (cosh, 1/2*e^(-x) + 1/2*e^x),
 (tanh, -(e^(-x) - e^x)/(e^(-x) + e^x))]

This is a Maxima problem :

(%i5) map(lambda([t],[t,demoivre(exponentialize(t(x)))]),[sin,cos,tan,sinh,cosh,tanh]);

(%o5) [[sin,sin(x)],[cos,cos(x)],[tan,sin(x)/cos(x)],[sinh,(%e^x-%e^-x)/2],
       [cosh,(%e^x+%e^-x)/2],[tanh,(%e^x-%e^-x)/(%e^x+%e^-x)]]

One also notes that sin(x)/cos(x) is not simplified in tan(x).

Reported on this ask question.

Related Maxima discussions:

Change History (7)

comment:1 Changed 5 years ago by tmonteil

  • Description modified (diff)

comment:2 Changed 5 years ago by tmonteil

  • Component changed from PLEASE CHANGE to symbolics

comment:3 Changed 5 years ago by tmonteil

Note that symbolic issues are collected on this wiki page.

comment:4 Changed 5 years ago by charpent

  • Report Upstream changed from Not yet reported upstream; Will do shortly. to Reported upstream. No feedback yet.

This has been reported as Maxima's bug #3358.

comment:5 Changed 10 months ago by charpent

  • Milestone changed from sage-8.1 to sage-duplicate/invalid/wontfix
  • Report Upstream changed from Reported upstream. No feedback yet. to Reported upstream. Developers deny it's a bug.
  • Status changed from new to needs_review

The inclusion of #10038 (which implements a Sage solution) in 9.5.beta0 may be considered as solving this problem (that won't be fixed in Maxima...). I propose to close this ticket.

Advice ?

comment:6 Changed 7 months ago by slelievre

  • Cc slelievre added
  • Description modified (diff)
  • Keywords maxima demoivre cosh sinh added
  • Reviewers set to Emmanuel Charpentier, Samuel Lelièvre
  • Status changed from needs_review to positive_review

comment:7 Changed 7 months ago by mkoeppe

  • Resolution set to invalid
  • Status changed from positive_review to closed
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