#216 limits involving x*atan(x) wrong

closed
nobody
5
2006-07-02
2003-01-21
No

limit(x*atan(x)/(x+1),x,inf) => %i * log(-1)/2 NO!

tlimit correctly gets %pi/2.

limit(x*atan(x)-log(x),x,inf) => minf NO!

tlimit correctly gets inf

Discussion

  • Stavros Macrakis

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    Maxima 5.5 on Windows

     
  • Stavros Macrakis

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    Another interesting case:

    expr: x*(atan(x)-%pi/2)

    limit(expr,x,inf) => minf NO!
    tlimit(expr,x,inf) => -1 OK!

    Maxima 5.9.0

     
  • Raymond Toy

    Raymond Toy - 2005-12-10

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    The first two limits now give the correct answers.

    However, the limit of x*(atan(x)-%pi/2) is returned
    unevaluated. Not very good, but certainly better than minf.

     
  • Robert Dodier

    Robert Dodier - 2006-04-09
    • labels: --> Lisp Core - Limit
     
  • Robert Dodier

    Robert Dodier - 2006-07-02
    • status: open --> closed
     
  • Robert Dodier

    Robert Dodier - 2006-07-02

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    Not observed in 5.9.3 or 5.9.3cvs. Closing this report as fixed.

    However for a couple of the examples tlimit gives an
    incorrect result. Bug report # 1515712 opened for that.

     

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