Re: Plotting an implicit function

*To*: mathgroup at smc.vnet.net*Subject*: [mg50591] Re: Plotting an implicit function*From*: mathma18 at hotmail.com ("G.L.Narasimham")*Date*: Sat, 11 Sep 2004 06:44:54 -0400 (EDT)*References*: <ftqtducifclt@legacy>*Sender*: owner-wri-mathgroup at wolfram.com

Plots fine, without needing to solve for r as function of M. f[r_, M_] = 1 + (-1 - 0.03*M^2 + 1.2*M)* r - (0.05*E^(r*M)/r - 0.05/r + E^(r*M)*(1 - 0.05*M)) ContourPlot[Evaluate[f[x, y]], {x, -10, 10}, {y, -1, 1}]; On 9 Sep 04 06:22:51 -0400 (EDT), David Friskin wrote: >I have the following implicit function: >f[r, M]=1 + (-1 - 0.03*M^2 + > 1.2*M)*r - (0.05*E^(r*M)/r - 0.05/r + E^(r*M)*(1 - 0.05*M))==0 > >where r is a function of M i.e. r(M). > >I would like to plot r(M) vs M, for {M,0,20}. > >I tried using > ImplicitPlot[{f[r,M] == 0},{M,0,20}], but Solve is having problems >finding the roots to my function. > >Could someone help me with the code to do this, perhaps using FindRoot >somehow? > >Thanks >David > >P.S. r > 0