Re: Indefinate integrals, erroneus Natural log?
- To: mathgroup at smc.vnet.net
- Subject: [mg77918] Re: Indefinate integrals, erroneus Natural log?
- From: dh <dh at metrohm.ch>
- Date: Tue, 19 Jun 2007 07:00:15 -0400 (EDT)
- References: <f55oor$j6f$1@smc.vnet.net>
Hi David, note that in your input there is no space between x and E. If I put the space in, version 5.1 and 6 give: E^(2*x)*(-1/4 + x/2) hope this helps, Daniel 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 > > >