Question about the derivative of Abs

*To*: mathgroup at smc.vnet.net*Subject*: [mg106097] Question about the derivative of Abs*From*: Sam Takoy <samtakoy at yahoo.com>*Date*: Fri, 1 Jan 2010 05:36:12 -0500 (EST)

Hi, I kind of asked this question before, but in a more confusing context, so now I would like to ask it by itself. In the course of my computations, I get Abs' and Abs''. It is applied to a positive number, so I think those values should be 1 and 0. However, Mathematica fails to simplify it. For example In[34]:= Abs'[2.0] Out[34]= \!\(\*SuperscriptBox["Abs", "\[Prime]", MultilineFunction->None]\)[2.] These expressions really mess up my answers. How do I get Mathematica to do these simplifications? Thanks Sam

**Follow-Ups**:**Re: Question about the derivative of Abs***From:*Patrick Scheibe <pscheibe@trm.uni-leipzig.de>

**Re: Question about the derivative of Abs***From:*Leonid Shifrin <lshifr@gmail.com>