Re: Indefinate integrals, erroneus Natural log?

*To*: mathgroup at smc.vnet.net*Subject*: [mg77895] Re: Indefinate integrals, erroneus Natural log?*From*: Szabolcs <szhorvat at gmail.com>*Date*: Tue, 19 Jun 2007 06:39:42 -0400 (EDT)*Organization*: University of Bergen*References*: <f55oor$j6f$1@smc.vnet.net>

David Rees wrote: > 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 xE, written without a space, is the name of a single symbol, while x E, with a space, is x*E (the product of x and E). Insert the missing space and you will get the result you expect.