solve implicit function



Is your equation missing a * between Rs and (rho_c ?   If so, maybe your 
equation has a (messy) solution
that involves the Lambert W function. Maxima doesn't have an equation 
solver that handles such equations
all that well.  I suggest that you solve the equation numerically --- try 
mnewton or friends.

Barton

maxima-bounces at math.utexas.edu wrote on 04/27/2009 07:18:55 AM:


> Hi,
> I would like to solve an equation with maximas's solve-function. The 
problem 
> is that it is an implicit function and the solve-function give no 
> result. How can I 
> solve this Problem. 
> 
> 
> (%i1)  eqn3: 1/w*sqrt(Rs(rho_c+0.2*Rs*h^2))*coth(sqrt(Rs/(rho_c+0.
> 2*Rs*h^2))*d)-Rc;
> 
> (%i2) Rs: 2.53;
> 
> (%i3) Rc: 0.395;
> 
> (%i4) h: 1.4e-6;
> 
> (%i5) d: 49e-6;
> 
> (%i6) w: 100e-6;
> 
> (%i7) solve(eqn3,rho_c);