Learn how easy it is to sync an existing GitHub or Google Code repo to a SourceForge project! See Demo

Close

#591 sqrt(1/z) - 1/sqrt(z) => 0

closed
nobody
5
2010-01-17
2004-08-17
Anonymous
No

sqrt(1/z) - 1/sqrt(z) => 0 in maxima 5.9.0.9beta2 and
stable 5.9.0.

If except z is real and negative, it's false but
sqrt(1/z) + 1/sqrt(z) => 0

See C(23) at
http://www.math.unm.edu/~wester/demos/ComplexDom
ain/Macsyma.problems

Cheers

Discussion

  • Robert Dodier
    Robert Dodier
    2006-07-31

    Logged In: YES
    user_id=501686

    Observed in 5.9.3cvs. A review of Wester's problems might
    turn up additional bugs in Maxima.

     
  • Robert Dodier
    Robert Dodier
    2006-07-31

    • labels: --> Lisp Core - Complex
     
  • Dieter Kaiser
    Dieter Kaiser
    2010-01-17

    • status: open --> closed
     
  • Dieter Kaiser
    Dieter Kaiser
    2010-01-17

    Fixed in simp.lisp revision 1.96. Maxima no longer simplifies sqrt(1/x) when the sign is not known.

    (%i2) sqrt(1/x);
    (%o2) sqrt(1/x)

    (%i3) assume(x>0)$

    (%i4) sqrt(1/x);
    (%o4) 1/sqrt(x)

    (%i5) sqrt(1/x)-1/sqrt(x);
    (%o5) 0

    (%i6) sqrt(1/-x)+1/sqrt(-x);
    (%o6) 0

    Closing this bug report as fixed.
    Dieter Kaiser