Re: Integer Solutions

*To*: mathgroup at smc.vnet.net*Subject*: [mg76991] Re: Integer Solutions*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Thu, 31 May 2007 03:27:09 -0400 (EDT)*Organization*: The Open University, Milton Keynes, UK*References*: <f3jh5v$dda$1@smc.vnet.net>

Jeff Albert wrote: > I need to find integer solutions for k in terms of t and d in the following > expression: > > k/(-((t - Log[E^t + d*k])/d)). > > Does Mathematica have any magic that will do this? > > Jeff A Jeff, Your request is not clear enough. You said you wanted to find a solution to a expression; however, an expression without any ==, <, <=, >, or >= symbol is neither an equation nor an inequality, so it is not solvable. You should provide a complete expression, say k/(-((t - Log[E^t + d*k])/d)) == 0 Then, you could use Reduce, for instance, as in In[1]:= expr = k/(-((t - Log[E^t + d*k])/d)) == 0; Reduce[expr, k, Integers] Reduce[expr, k, Complexes] Out[2]= False Out[3]= t - Log[E^t] != 0 && (d == 0 || k == 0) Regards, Jean-Marc