Re: FullSimplify with Pi

*To*: mathgroup at smc.vnet.net*Subject*: [mg84132] Re: [mg84129] FullSimplify with Pi*From*: Carl Woll <carlw at wolfram.com>*Date*: Tue, 11 Dec 2007 06:06:46 -0500 (EST)*References*: <200712110320.WAA26066@smc.vnet.net>

Uberkermit wrote: >Greetings, > >I would like to simplify an expression involving Pi. Actually, >simplifying the expression isn't hard, getting Mathematica to >recognize the simplification is the hard part. Consider: > >Assuming[Element[x, Reals], > FullSimplify[Log[1/Sqrt[2 Pi] Exp[x]]]] > >Mathematica doesn't do anything to simplify this. However, replacing >the symbol Pi with any other variable in the above leads to the >trivial substitutions. > >By trivial, I mean: > Log[Exp[x]] = x, and Log[a/b] = Log[a] - Log[b]. > >Why does Pi confuse Mathematica so?? > >Thanks, >-Chris > > Use PowerExpand: In[111]:= PowerExpand[Log[1/Sqrt[2 Pi] Exp[x]], Assumptions -> Element[x, Reals]] Out[111]= x+1/2 (-log(2)-log(\[Pi])) Carl Woll Wolfram Research

**References**:**FullSimplify with Pi***From:*Uberkermit <chris.r.sims@gmail.com>