Solving equations involving Ln function

*To*: mathgroup at smc.vnet.net*Subject*: [mg19851] Solving equations involving Ln function*From*: Satyajit Bose <sgb2 at columbia.edu>*Date*: Sun, 19 Sep 1999 01:20:35 -0400*Organization*: Columbia University*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I am trying to solve some equations involving the natural log function. Mathematica 3.0 will not let me solve them since the relations are non-algebraic. Is there any way to restrict the domain to positive reals or get Mathematica to use the exponential as an inverse, so that I can get a solution. I know that this can be done in another system, presumably because it is less careful about atypical domain restrictions. Here is my input line and results in the kernel: In[1]:= Solve[Log[x]+delta*v==Log[(1-delta)*x/(1-delta^2)]+delta*Log[(1-delta)*d elta*x/(1-delta^2)]+delta^2*v,x] Solve::tdep: The equations appear to involve transcendental functions of the variables in an essentially non-algebraic way. Out[1]= Solve[delta v + Log[x] == 2 (1 - delta) x (1 - delta) delta x > delta v + Log[-------------] + delta Log[-------------------], x] 2 2 1 - delta 1 - delta I am hoping to get a solution that looks like this: x -> exp[v*(1-delta)]*(1+delta)^(1+1/delta)/delta) Thank you for all your help. Sayajit Bose -- Satyajit Bose Department of Economics New York, NY 10027 Columbia University (212) 665-8208 http://www.columbia.edu/~sgb2 sgb2 at columbia.edu