Re: Integration..Constants
- To: mathgroup at smc.vnet.net
- Subject: [mg5139] Re: [mg5119] Integration..Constants
- From: Sherman Reed <Sherman.Reed at worldnet.att.net>
- Date: Wed, 6 Nov 1996 01:33:00 -0500
- Sender: owner-wri-mathgroup at wolfram.com
At 03:04 AM 10/31/96 +0000, you wrote: >I have tried several times to perform an integration(math..2.2.3)B >similar to the following. > >In[1]:=Integrate[(ao+x)^-1 (bo^-2), x] > >The results, however, are always incorrect: > >Out[1]=-ln(-ao+x) <---where the constant "ao" should be positive. > >Note: The above is not the exact problem and solution. It is only an >example of the type of problem I have been having with the program. > >I have tried to specify the value of "ao" before integrating: > >In[1]:=SetAttribute[ao, Constant] > >or > >In[1]:=SetAttribute[ao, Protected] > >or a combination of the two. > >I have also tried: > >In[1]:=ao/. Sign[ao]=1 > >To try and get a positive result. I have also tried MathCad 6.0+ and >gotten the same results. It appears to be a problem for both programs. >(For those that might think that I am the one with the problem, I would >like to say that a tenured prof and a postdoc agreed that there is a >problem with the program). If you know of a solution, or can point me in >a different direction, I would greatly appreciate it. This would save me >from having to contact Wolfram about his program. > > >-- >---------------------------------- -Dennis M. Winters - >-P.O. BOX 21215 - >-EMORY UNIVERSITY - >-ATLANTA, GA 30322 - >-dwint01 at emory.edu - >-or winters at euch6h.chem.emory.edu- >---------------------------------- Dennis, I have 2.2.2 on a notebook and I get the correct result, specifically In[3]:=Integrate[(ao+x)^-1*(bo^-2),x] Out[3]=(Log[ao + x]\/bo\^2\) In[4]:=Integrate[(ao+x)^-1,x] Out[4]=Log[ao+x] I have 3.0 on a Pent 166, Win 95, and I get the exact same result. I also have 2.2.1 on a NeXT which gets the same result. I would be glad to look at your problem, if you care to share it in more detail. I am more impressed with results than either postdocs or tenured faculty. I taught Numerical Methods using Mma for 5 years at UTA. Sherman C. Reed Sr. Lecturer, University of Texas at Arlington (Retired) AT&T-Bell Laboratories (Retired)