#1717 integrate(log(sec(x)),x) --> lisp error

closed
nobody
5
2009-08-19
2009-07-26
No

(%i4) integrate(log(sec(x)),x);
Maxima encountered a Lisp error:

(%i5) build_info();
Maxima version: 5.18.1
Maxima build date: 20:57 4/19/2009
host type: i686-pc-mingw32
lisp-implementation-type: GNU Common Lisp (GCL)
lisp-implementation-version: GCL 2.6.8
(%o5)

Discussion

  • Dieter Kaiser

    Dieter Kaiser - 2009-07-26

    With the current CVS version and in a fresh Maxima this problem is not present:

    Maxima version: 5.18post
    Maxima build date: 0:14 7/27/2009
    host type: i686-pc-linux-gnu
    lisp-implementation-type: CLISP
    lisp-implementation-version: 2.44.1 (2008-02-23) (built 3436700604) (memory 3457635278)

    (%i4) integrate(log(sec(x)),x);
    (%o4) (x*log(sin(2*x)^2+cos(2*x)^2+2*cos(2*x)+1)
    +2*%i*x*atan2(sin(2*x),cos(2*x)+1)-%i*li[2](-%e^(2*%i*x))-%i*x^2)
    /2
    +x*log(sec(x))

    I have not checked the result.

    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2009-08-19

    As reported in the last posting the integral of this bug report works. The answer does not look nice but can be shown to be equivalent to the result

    -(%i*li[2](-%e^(2*%i*x)))/2-(%i*x^2)/2+x*log(1+%e^(2*%i*x))+x*log(sec(x))

    from wolfram alpha.

    Closing this bug report as "works for me".

    Remark: Related integrals with integrands like log(sin(x)) or log(cos(x)) give an answer too.

    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2009-08-19
    • status: open --> closed
     

Log in to post a comment.

Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:





No, thanks