Re: can't MATHEMATICA simplify simple expressions?

*To*: mathgroup at smc.vnet.net*Subject*: [mg51540] Re: can't MATHEMATICA simplify simple expressions?*From*: adam.smith at hillsdale.edu (Adam Smith)*Date*: Thu, 21 Oct 2004 22:21:09 -0400 (EDT)*References*: <cl4tg0$8g7$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

The problem is that you are assuming that "a" is a real number. While this is normal for most humans, it need not be in a strict mathematical sense. By default Mathematica assumes all variables can be complex. For a complex number the result is not simply a^3. You can place conditions on the simplicication: For example if a>0 In[4]:= FullSimplify [ (a^2)^(3/2),a>0 ] Out[4]= a^3 For a simply a real number In[5]:= FullSimplify [ (a^2)^(3/2),Element[a,Reals] ] Out[5]= Abs[a]^3 Cole Turner <REMOVEcole.tuner at liwest.at> wrote in message news:<cl4tg0$8g7$1 at smc.vnet.net>... > if I enter: > > FullSimplify [ (a^2)^(3/2) ] > > (in correct MATHEMATICA syntax, the program does not yield the correct > result, a^3 ... > > why is that? > > thanks!