Re: Integration...

*To*: mathgroup at smc.vnet.net*Subject*: [mg24175] Re: Integration...*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 28 Jun 2000 22:50:56 -0400 (EDT)*Organization*: Universitaet Leipzig*References*: <8jc70h$df6@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, assuming you have dg[t] and df[t] somewhere and g[a] and f[a] are numbers you can use NDSolve[] with sol=NDSolve[{f'[t]==df[t],g'[t]==dg[t],g[0]==g[a],f[0]=f[a]},{f[t],g[t]},{y,0,10^10*Pi}]; ParametricPlot[ Evaluate[{g[t],f[t]} /. sol] {t,0,10^10 Pi} ] Regards Jens "Yeung, Matthew" wrote: > > Dear Sir, > > I am a Mathematica user and am having problems with one particular task that > I have to perform. > > I have 2 function, {f'(t),g'(t)}, that are unintegrable. I wish to plot the > parametric curve {f(t),g(t)} for a<t<b, say, but do not wish to use > NIntegrate as it will give me the result {f(T)-f(a),g(T)-g(a)}. > > Is there a way that I can find {f(a),g(a)} so that I can use NIntegrate; or > is it possible to evaluate the integral at one point? > > Thanks for your heklp and I look forward to hearing from you soon. > > Regards, > > Matt Yeung