Re: Resolve a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg89706] Re: [mg89697] Resolve a function*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Wed, 18 Jun 2008 06:40:40 -0400 (EDT)*Reply-to*: hanlonr at cox.net

f[r_] = 144/10*((2/Sqrt[r^2 + R^2]) - 1/r); soln = Solve[f[r] == 0, r] {{r -> -(R/Sqrt[3])}, {r -> R/Sqrt[3]}} Simplify[f[r] /. soln, R > 0] {(144*Sqrt[3])/(5*R), 0} Simplify[f[r] /. soln, R < 0] {0, -((144*Sqrt[3])/(5*R))} ---- maria <m.massaouti at windowslive.com> wrote: > Dear all, > I am new with mathematica. I would be grateful if someone could tell > me how can I find the general solutions of the r for the following > function f(r_) = 14.4* ((2/Sqrt[r^2 + R^2]) - 1/r ) (where > R=constant). I just want to express the function as r =.....*f. Is > this possible with mathematica. > Thank you. >