MathGroup Archive 2008

[Date Index] [Thread Index] [Author Index]

Search the Archive

RE: How to Integrate[Abs[x]]?


Hello,

It's because Mathematica considers x as a Complex number.
So you can do it like this :

In[35]:= Assuming[Element[x, Reals], Integrate[Abs[x], x]]

Out[35]= Piecewise[{{-(x^2/2), x <= 0}}, x^2/2]


Or like this :

In[36]:= Integrate[Sqrt[x^2], x]

Out[36]= (x*Sqrt[x^2])/2


Regards,

F.Jaccard

-----Message d'origine-----
De : Thomas Dybdahl Ahle [mailto:lobais at gmail.com]
Envoy=E9 : vendredi, 29. ao=FBt 2008 10:26
=C0 : mathgroup at smc.vnet.net
Objet : [mg91624] How to Integrate[Abs[x]]?

On my Ti calculater |x| is easily integrated to |x|*x/2, but when I type =
Integrate[Abs[x],x] in mathematica, it seams like it can't find the =
solution.
Is there anything I'll have to do, to make mathematica find the =
solution?



  • Prev by Date: animated faces of polygon
  • Next by Date: Re: How to Integrate[Abs[x]]?
  • Previous by thread: How to Integrate[Abs[x]]?
  • Next by thread: Re: How to Integrate[Abs[x]]?