Re: Indefinate integrals, erroneus Natural log?

*To*: mathgroup at smc.vnet.net*Subject*: [mg77876] Re: Indefinate integrals, erroneus Natural log?*From*: dimitris <dimmechan at yahoo.com>*Date*: Tue, 19 Jun 2007 06:29:57 -0400 (EDT)*References*: <f55oor$j6f$1@smc.vnet.net>

Hi David. Yo forget a space for multiplication operator. That is, In[2]:= Integrate[x*E^(2*x), x] Out[2]= E^(2*x)*(-(1/4) + x/2) Dimitris / David Rees : > Hi, > > In preparation for a major exam tomorrow, I was just checking some of my > answers to past-papers with mathematica, I fed it this input: > > In[117]:= > \!\(\[Integral]\((xE\^\(2 x\))\) \[DifferentialD]x\) > Out[117]= > \!\(xE\^\(2\ x\)\/\(2\ Log[xE]\)\) > > I marked myself wrong and moved on to the next question, but I happened > accross the actual mark-scheme which said I was correct. It gave this > answer: > > ((1/2)xE^(2x))-(1/4)e^(2x) > > My Integral calculus isn't so strong, so I don't know if the additional > natural log should be there, or if the two expressions are identical. > > Thanks