Menu

#2097 a integrate(sin(exp(x), x) is different to Mathematica

closed
nobody
5
2010-10-31
2010-10-31
No

The results of integrate(sin(exp(x), x) is different from Mathematica 7
-------------------------------------------------------------
Maxima version: 5.22.1
Maxima build date: 11:48 8/13/2010
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8
-------------------------------------------------------------

maxima:
b(t):= expand(float(subst(x=t, integrate(sin(exp(x)), x))));
makelist(b(t), t, 0, 3);
[-0.62471325642771,0.25024394235267,-0.073778082688431,-0.018588783055919]

Mathematica 7:
Table[SinIntegral[Exp[x]], {x, 0, 3}] // N
{0.946083, 1.82104, 1.49702, 1.55221}

Discussion

  • Dieter Kaiser

    Dieter Kaiser - 2010-10-31
    • status: open --> closed
     
  • Dieter Kaiser

    Dieter Kaiser - 2010-10-31

    The function SinIntegral in Mathematica corresponds in Maxima with expintegral_si.

    (%i1) b(x):=float(expintegral_si(exp(x)));
    (%o1) b(x) := float(expintegral_si(exp(x)))
    (%i2) makelist(b(t),t,0,3);
    (%o2) [0.946083070367183, 1.821040269147567, 1.497018244106465,
    1.552207543269926]

    This is the result of Mathematica too. The definition of the Exponential Integral Si is

    integrate(sin(t)/t,t,0,x)

    Maxima can not solve this integral symbolically.

    Closing this bug report as "works for me".

    Dieter Kaiser

     
  • Aleksas Domarkas

    Proposition.
    integrate(sin(exp(x)), x)+%pi/2 (Maxima)
    =Integrate[Sin[Exp[x]], x] (Mathematica)
    =integrate(sin(exp(x)), x) (Maple)

    Maxima:
    (%i1) integrate(sin(exp(x)), x)+%pi/2$
    (%i2) makelist(subst(x=k,%),k,0,3)$
    (%i3) float(%)$
    (%i4) expand(%);
    (%o4) [0.94608307036718,1.821040269147567,1.497018244106465,1.552207543738978]

    Mathematica:
    In[1]:= Integrate[Sin[Exp[x]], x]
    Out[1]= SinIntegral[E^x]
    In[2]:= Table[%, {x, 0, 3}]
    Out[42]= {SinIntegral[1], SinIntegral[E], SinIntegral[E^2],
    SinIntegral[E^3]}
    In[3]:= N[%]
    Out[3]= {0.946083, 1.82104, 1.49702, 1.55221}

    Maple:
    > integrate(sin(exp(x)), x);
    Si(exp(x))
    > seq(subs(x=k,%),k=0..3);
    Si(exp(0)), Si(exp(1)), Si(exp(2)), Si(exp(3))
    > evalf(%);
    0.9460830704, 1.821040269, 1.497018244, 1.552207544

     

Log in to post a comment.