Re: system of equations
- To: mathgroup at smc.vnet.net
- Subject: [mg73362] Re: system of equations
- From: "dimitris" <dimmechan at yahoo.com>
- Date: Wed, 14 Feb 2007 05:16:35 -0500 (EST)
- References: <eqs96r$iie$1@smc.vnet.net>
Hi Lena. Your post is very unreadable. For example the two variables appears as =E2=80=9Ckheute=E2=80=9D and =E2=80=9CMheute=E2=80== 9D Also they appeared a lot of unnecessary "=" so I was not able to figure out what is going on. Try to repost the mail. Dimitris =CF/=C7 Lena Calahorrano =DD=E3=F1=E1=F8=E5: > Maybe someone can help me solving a system of equations: > > I have two equations each of which depends on the the two variables =E2= =80 > =9Ckheute=E2=80=9D and =E2=80=9CMheute=E2=80=9D and I= am interested in the > value of these two variables. > > > > The equations look like this, where all parameters are known: > > > > kheute=C5=A0l*(1/(1+n)*((1-a)*A*Part[f[t],1]^a*(b^2/f+b/f)-(1-a)*A*kh= eute^a > /(1+a*A*kheute^(a-1)-d))+1/(1+n)^2*b^2/f*((1-a)*A*Part[f[t],1]^a+(1+a*A*P= art[f[t],1]^(a-1)-d)*(1-a)*A*Part[f[t-1],1]))/((2+n)/(1+n)+Mheute/bev) > > > > kheute====l*(1/(1+An)*((1-a)*A*Part[Af[t],1]^a*(b^2/f+b/f)-(1-a)*= A*kheute^a/(1+a*A*kheute^(a-1)-d))+1/(1+An)^2*b^2/f*((1-a)*A*Part[Af[t],1]^= a+(1+a*A*Part[Af[t],1]^(a-1)-d)*(1-a)*A*Part[Af[t-1],1]))/((2+An)/(1+An)-Mh= eute/bevA) > > > > > > I can express =E2=80=9Ckheute=E2=80=9D as a function of =E2= =80=9CMheute=E2=80=9D, I can plot the two functions and see where= they intersect: > > > > > > solInland==Solve[Simplify[kheute=C5=A0l*(1/(1+n)*((1-a)*A*Part[f[= t],1]^a*(b^2/f+b/f)-(1-a)*A*kheute^a/(1+a*A*kheute^(a-1)-d))+1/(1+n)^2*b^2/= f*((1-a)*A*Part[f[t],1]^a+(1+a*A*Part[f[t],1]^(a-1)-d)*(1-a)*A*Part[f[t-1],= 1]))/((2+n)/(1+n)+Mheute/bev)],Mheute] > > > > mInland==Part[Mheute/.solInland,1] > > f[kheute_]:==mInland > > grafikInland==Plot[f[kheute],{kheute,0.04,0.14},PlotStyle=C2=AE{R= GBColor[1,0, 0.501961]}]; > > > > > > solAusland==Solve[Simplify[kheute====l*(1/(1+An)*((1-a)*A*Par= t[Af[t],1]^a*(b^2/f+b/f)-(1-a)*A*kheute^a/(1+a*A*kheute^(a-1)-d))+1/(1+An)^= 2*b^2/f*((1-a)*A*Part[Af[t],1]^a+(1+a*A*Part[Af[t],1]^(a-1)-d)*(1-a)*A*Part= [Af[t-1],1]))/((2+An)/(1+An)-Mheute/bevA)],Mheute] > > mAusland==Part[Mheute/.solAusland,1] > > g[kheute_]:==mAusland > > grafikAusland==Plot[g[kheute],{kheute,0.04,0.14}]; > > > > vergl==Show[grafikInland,grafikAusland]; > > > > > > But when I try to solve for =E2=80=9Ckheute=E2=80=9D, Mathema= tica runs forever. This is a problem because I eventually want to compute a= bout 50 more steps. > > > > > > Solve[Simplify[mInland=C5=A0mAusland],kheute] > > > > > > Is there a better way to do this kind of computation? > > > > Best regards, > > Lena Calahorrano > > > > > > > > > > Lena Calahorrano > > Lehr- und Forschungsgebiet > > Internationale Wirtschaftsbeziehungen > > RWTH Aachen > > Templergraben 64 > > 52056 Aachen > > 0241-80-93934 > > lena.calahorrano at rwth-aachen.de > http://www.iw.rwth-aachen.de